From 37f3a54fc476f1c47fd399e4a3ee2ebd7654b7ff Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Sat, 8 Oct 2016 23:36:13 -0700
Subject: [PATCH 01/59] Added Canvas class

---
 src/Plots/Canvas.php | 8 ++++++++
 1 file changed, 8 insertions(+)
 create mode 100644 src/Plots/Canvas.php

diff --git a/src/Plots/Canvas.php b/src/Plots/Canvas.php
new file mode 100644
index 000000000..ed50dd360
--- /dev/null
+++ b/src/Plots/Canvas.php
@@ -0,0 +1,8 @@
+<?php
+
+namespace MathPHP\Plots;
+
+class Canvas
+{
+
+}

From 98e5ffe217792155e90a42033b9d59c1bfbe577b Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Sat, 8 Oct 2016 23:37:14 -0700
Subject: [PATCH 02/59] Added constructor and parameter visibility

---
 src/Plots/Canvas.php | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/Plots/Canvas.php b/src/Plots/Canvas.php
index ed50dd360..cbc3e63ab 100644
--- a/src/Plots/Canvas.php
+++ b/src/Plots/Canvas.php
@@ -4,5 +4,14 @@
 
 class Canvas
 {
+    protected $width;
+    protected $height;
+    protected $canvas;
 
+    public function __construct($width = 600, $height = 600)
+    {
+        $this->width  = $width;
+        $this->height = $height;
+        $this->canvas = imagecreate($width, $height);
+    }
 }

From fdb8063d17af2b10fbd62e3239da593658d6ba59 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Sat, 8 Oct 2016 23:37:41 -0700
Subject: [PATCH 03/59] Added addPlot() method

---
 src/Plots/Canvas.php | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/Plots/Canvas.php b/src/Plots/Canvas.php
index cbc3e63ab..9b63941af 100644
--- a/src/Plots/Canvas.php
+++ b/src/Plots/Canvas.php
@@ -7,6 +7,7 @@ class Canvas
     protected $width;
     protected $height;
     protected $canvas;
+    protected $plot;
 
     public function __construct($width = 600, $height = 600)
     {
@@ -14,4 +15,10 @@ public function __construct($width = 600, $height = 600)
         $this->height = $height;
         $this->canvas = imagecreate($width, $height);
     }
+
+    public function addPlot($padding = 0)
+    {
+        $this->plot = new Plot($padding);
+        return $this->plot;
+    }
 }

From 356bcd3dc3de0e410f87991e00bdb1810a1f863e Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Sat, 8 Oct 2016 23:38:23 -0700
Subject: [PATCH 04/59] Added Plot class

---
 src/Plots/Plot.php | 8 ++++++++
 1 file changed, 8 insertions(+)
 create mode 100644 src/Plots/Plot.php

diff --git a/src/Plots/Plot.php b/src/Plots/Plot.php
new file mode 100644
index 000000000..489ef514d
--- /dev/null
+++ b/src/Plots/Plot.php
@@ -0,0 +1,8 @@
+<?php
+
+namespace MathPHP\Plots;
+
+class Plot extends Canvas
+{
+
+}

From d6b3bcad2aee3f6d58d4d01ec607d3077d33ae6f Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Sat, 8 Oct 2016 23:40:30 -0700
Subject: [PATCH 05/59] Added basic draw() method

---
 src/Plots/Plot.php | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/Plots/Plot.php b/src/Plots/Plot.php
index 489ef514d..5ce552ab6 100644
--- a/src/Plots/Plot.php
+++ b/src/Plots/Plot.php
@@ -4,5 +4,11 @@
 
 class Plot extends Canvas
 {
-
+    public function draw($canvas, $width, $height)
+    {
+        $black = imagecolorallocate($canvas, 0, 0, 0);
+        header('Content-type: image/png');
+        // Draw something here
+        return $canvas;
+    }
 }

From 6208f65f81e6fcb8930b8644f941bd70f9e0169e Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Sat, 8 Oct 2016 23:40:59 -0700
Subject: [PATCH 06/59] Added constructor to Plot and method visibility

---
 src/Plots/Plot.php | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/Plots/Plot.php b/src/Plots/Plot.php
index 5ce552ab6..8cc6c4bf8 100644
--- a/src/Plots/Plot.php
+++ b/src/Plots/Plot.php
@@ -4,11 +4,19 @@
 
 class Plot extends Canvas
 {
+    private $padding;
+
+    public function __construct($padding)
+    {
+        $this->padding = $padding;
+    }
+
     public function draw($canvas, $width, $height)
     {
+        $padding = $this->padding;
         $black = imagecolorallocate($canvas, 0, 0, 0);
         header('Content-type: image/png');
-        // Draw something here
+        imagerectangle($canvas, $padding, $padding, $width - $padding, $height - $padding, $black);
         return $canvas;
     }
 }

From 63fee35adfd5eaabf5eb2e56e596e70adab0a76a Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Sat, 8 Oct 2016 23:41:14 -0700
Subject: [PATCH 07/59] Added setPadding() method to Plot

---
 src/Plots/Plot.php | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/Plots/Plot.php b/src/Plots/Plot.php
index 8cc6c4bf8..0aabcc2ae 100644
--- a/src/Plots/Plot.php
+++ b/src/Plots/Plot.php
@@ -11,6 +11,11 @@ public function __construct($padding)
         $this->padding = $padding;
     }
 
+    public function setPadding($padding)
+    {
+        $this->padding = $padding;
+    }
+
     public function draw($canvas, $width, $height)
     {
         $padding = $this->padding;

From 2338c4b3a61635433aa49dd5b70c0c656e17294c Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Sat, 8 Oct 2016 23:41:32 -0700
Subject: [PATCH 08/59] Added save() method to Canvas

---
 src/Plots/Canvas.php | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/src/Plots/Canvas.php b/src/Plots/Canvas.php
index 9b63941af..158ee8c3d 100644
--- a/src/Plots/Canvas.php
+++ b/src/Plots/Canvas.php
@@ -21,4 +21,14 @@ public function addPlot($padding = 0)
         $this->plot = new Plot($padding);
         return $this->plot;
     }
+
+    public function save()
+    {
+        $width  = $this->width;
+        $height = $this->height;
+        $canvas = imagecreate($width, $height);
+        imagecolorallocate($canvas, 255, 255, 255);
+        $canvas = $this->plot->draw($canvas, $width, $height);
+        imagejpeg($canvas, 'image-' . rand() . '.jpg');
+    }
 }

From acf8b41a59562c22a01ba6cc2728e454c6be1801 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Sat, 8 Oct 2016 23:51:31 -0700
Subject: [PATCH 09/59] Added comments to map out development of Plot class

---
 src/Plots/Plot.php | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/src/Plots/Plot.php b/src/Plots/Plot.php
index 0aabcc2ae..15405fadf 100644
--- a/src/Plots/Plot.php
+++ b/src/Plots/Plot.php
@@ -18,10 +18,27 @@ public function setPadding($padding)
 
     public function draw($canvas, $width, $height)
     {
+        // Build convenience variables for canvas/plot measures
         $padding = $this->padding;
+
+        // Create axes
         $black = imagecolorallocate($canvas, 0, 0, 0);
-        header('Content-type: image/png');
         imagerectangle($canvas, $padding, $padding, $width - $padding, $height - $padding, $black);
+
+        // Define input function
+
+        // calculate canvas step size and function step size
+
+        // Calculate function values, min, and max
+
+        // Draw y-axis values, dashes
+
+        // Draw x-axis values, dashes
+
+        // Draw title, x-axis title, y-axis title
+
+        // Draw graph
+
         return $canvas;
     }
 }

From f8c1253bb007d606f7e6d45bc0bb9efa42001eb4 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Sun, 9 Oct 2016 00:15:05 -0700
Subject: [PATCH 10/59] Added convenience variables for canvas/plot measures

---
 src/Plots/Plot.php | 33 ++++++++++++++++++++++-----------
 1 file changed, 22 insertions(+), 11 deletions(-)

diff --git a/src/Plots/Plot.php b/src/Plots/Plot.php
index 15405fadf..a7c31e6d7 100644
--- a/src/Plots/Plot.php
+++ b/src/Plots/Plot.php
@@ -4,22 +4,33 @@
 
 class Plot extends Canvas
 {
-    private $padding;
-
-    public function __construct($padding)
-    {
-        $this->padding = $padding;
-    }
-
-    public function setPadding($padding)
+    public function __construct()
     {
-        $this->padding = $padding;
+        parent::__construct();
+        $this->x_label = "x-label";
+        $this->y_label = "y-label";
     }
 
-    public function draw($canvas, $width, $height)
+    public function draw($canvas)
     {
         // Build convenience variables for canvas/plot measures
-        $padding = $this->padding;
+        $width = $this->width;
+        $height = $this->height;
+        $padding = 50;
+        list($x_shift, $y_shift) = [
+            isset($this->y_label) ? 1 : 0,
+            isset($this->x_label) ? 1 : 0,
+        ];
+        list($graph_start_x, $graph_start_y, $graph_end_x, $graph_end_y) = [
+            (1 + $x_shift)*$padding,
+            imagesy($canvas) - (1 + $y_shift)*$padding,
+            imagesx($canvas) - $padding,
+            $padding
+        ];
+        list($graph_width, $graph_height) = [
+            imagesx($canvas) - (2 + $x_shift)*$padding,
+            imagesy($canvas) - (2 + $y_shift)*$padding
+        ];
 
         // Create axes
         $black = imagecolorallocate($canvas, 0, 0, 0);

From 4bd2b00b0c26b89f8a83a16d2265c74825b18a67 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Sun, 9 Oct 2016 00:17:49 -0700
Subject: [PATCH 11/59] Added rectangle for plot axes

---
 src/Plots/Plot.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Plots/Plot.php b/src/Plots/Plot.php
index a7c31e6d7..16dee9f32 100644
--- a/src/Plots/Plot.php
+++ b/src/Plots/Plot.php
@@ -34,7 +34,7 @@ public function draw($canvas)
 
         // Create axes
         $black = imagecolorallocate($canvas, 0, 0, 0);
-        imagerectangle($canvas, $padding, $padding, $width - $padding, $height - $padding, $black);
+        imagerectangle($canvas, $graph_start_x, $graph_end_y, $graph_end_x, $graph_start_y, $black);
 
         // Define input function
 

From 19d52db72cc6efc581fd6360c6f1682decf17ebd Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Sun, 9 Oct 2016 00:20:29 -0700
Subject: [PATCH 12/59] Defined input function and function domain

---
 src/Plots/Plot.php | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/Plots/Plot.php b/src/Plots/Plot.php
index 16dee9f32..1b5b595c3 100644
--- a/src/Plots/Plot.php
+++ b/src/Plots/Plot.php
@@ -9,6 +9,9 @@ public function __construct()
         parent::__construct();
         $this->x_label = "x-label";
         $this->y_label = "y-label";
+        $this->function = function ($x) { return $x; };
+        $this->start = 0;
+        $this->end = 10;
     }
 
     public function draw($canvas)
@@ -37,6 +40,9 @@ public function draw($canvas)
         imagerectangle($canvas, $graph_start_x, $graph_end_y, $graph_end_x, $graph_start_y, $black);
 
         // Define input function
+        $function = $this->function;
+        $function_start = $this->start;
+        $function_end = $this->end;
 
         // calculate canvas step size and function step size
 

From d3b765c47112b0ae5e708e2f8692ad301a9c6793 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Sun, 9 Oct 2016 00:22:11 -0700
Subject: [PATCH 13/59] Calculated graph step size and function step size

---
 src/Plots/Plot.php | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/Plots/Plot.php b/src/Plots/Plot.php
index 1b5b595c3..09f387f90 100644
--- a/src/Plots/Plot.php
+++ b/src/Plots/Plot.php
@@ -44,7 +44,11 @@ public function draw($canvas)
         $function_start = $this->start;
         $function_end = $this->end;
 
-        // calculate canvas step size and function step size
+        // Calculate canvas step size and function step size
+        $n             = 1000;
+        $graph_step_x  = $graph_width/$n;
+        $graph_step_y  = $graph_height/$n;
+        $function_step = ($b - $a)/$n;
 
         // Calculate function values, min, and max
 

From 1bc8e41d46a6d0964bc54a1e9e7bbc051164bee9 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Sun, 9 Oct 2016 00:24:55 -0700
Subject: [PATCH 14/59] Calculate function values, min, max, and function scale

---
 src/Plots/Plot.php | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/src/Plots/Plot.php b/src/Plots/Plot.php
index 09f387f90..200856cd6 100644
--- a/src/Plots/Plot.php
+++ b/src/Plots/Plot.php
@@ -16,7 +16,7 @@ public function __construct()
 
     public function draw($canvas)
     {
-        // Build convenience variables for canvas/plot measures
+        // Build convenience variables for graph measures
         $width = $this->width;
         $height = $this->height;
         $padding = 50;
@@ -39,18 +39,25 @@ public function draw($canvas)
         $black = imagecolorallocate($canvas, 0, 0, 0);
         imagerectangle($canvas, $graph_start_x, $graph_end_y, $graph_end_x, $graph_start_y, $black);
 
-        // Define input function
+        // Define input function and function domain
         $function = $this->function;
-        $function_start = $this->start;
-        $function_end = $this->end;
+        $start    = $this->start;
+        $end      = $this->end;
 
-        // Calculate canvas step size and function step size
+        // Calculate graph step size and function step size
         $n             = 1000;
         $graph_step_x  = $graph_width/$n;
         $graph_step_y  = $graph_height/$n;
-        $function_step = ($b - $a)/$n;
+        $function_step = ($end - $start)/$n;
 
         // Calculate function values, min, and max
+        $image = [];
+        for ($i = 0; $i <= $n; $i++) {
+            $image[] = $function($start + $i*$function_step);
+        }
+        $min = min($image);
+        $max = max($image);
+        $function_scale = $graph_height/($max - $min);
 
         // Draw y-axis values, dashes
 

From ff51fd2746f0f022fdb43ac477d955ee06f0373a Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Sun, 9 Oct 2016 00:28:04 -0700
Subject: [PATCH 15/59] Draw y-axis values and dashes

---
 src/Plots/Plot.php | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/src/Plots/Plot.php b/src/Plots/Plot.php
index 200856cd6..70708c128 100644
--- a/src/Plots/Plot.php
+++ b/src/Plots/Plot.php
@@ -50,7 +50,7 @@ public function draw($canvas)
         $graph_step_y  = $graph_height/$n;
         $function_step = ($end - $start)/$n;
 
-        // Calculate function values, min, and max
+        // Calculate function values, min, max, and function scale
         $image = [];
         for ($i = 0; $i <= $n; $i++) {
             $image[] = $function($start + $i*$function_step);
@@ -60,6 +60,23 @@ public function draw($canvas)
         $function_scale = $graph_height/($max - $min);
 
         // Draw y-axis values, dashes
+        $fontpath = realpath('.'); //replace . with a different directory if needed
+        putenv('GDFONTPATH='.$fontpath);
+        $count = 9;
+        $font = 'arial.ttf';
+        $size = 10;
+        $angle = 0;
+        $length1 = 1;
+        $length2 = 5;
+        $white = imagecolorallocate($canvas, 255, 255, 255);
+        $style = array_merge(array_fill(0, $length1, $black), array_fill(0, $length2, $white));
+        imagesetstyle($canvas, $style);
+        for ($i = 0; $i <= $count; $i++) {
+            imagettftext($canvas, $size, $angle, $graph_start_x - $padding*0.75, $size*0.5 + $graph_start_y - $i*($graph_height/$count), $black, $font, round(($min + $i*($max - $min)/$count), 1));
+            if ($i !== 0 and $i !== $count) {
+                imageline($canvas, $graph_start_x, $graph_start_y - $i*($graph_height/$count), $graph_end_x, $graph_start_y - $i*($graph_height/$count), IMG_COLOR_STYLED);
+            }
+        }
 
         // Draw x-axis values, dashes
 

From f4f8e95a1eca61af5c1a87fb3ff213f0d560a9d7 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Sun, 9 Oct 2016 00:33:44 -0700
Subject: [PATCH 16/59] Draw x-axis values and grid

---
 src/Plots/Plot.php | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/src/Plots/Plot.php b/src/Plots/Plot.php
index 70708c128..898f0a642 100644
--- a/src/Plots/Plot.php
+++ b/src/Plots/Plot.php
@@ -59,7 +59,7 @@ public function draw($canvas)
         $max = max($image);
         $function_scale = $graph_height/($max - $min);
 
-        // Draw y-axis values, dashes
+        // Draw y-axis values and grid
         $fontpath = realpath('.'); //replace . with a different directory if needed
         putenv('GDFONTPATH='.$fontpath);
         $count = 9;
@@ -78,7 +78,14 @@ public function draw($canvas)
             }
         }
 
-        // Draw x-axis values, dashes
+        // Draw x-axis values and grid
+        $newcount = 9;
+        for ($i = 0; $i <= $newcount; $i++) {
+            imagettftext($canvas, $size, $angle, $graph_start_x + $i*($graph_width/$newcount), $graph_start_y + $padding/2, $black, $font, round(($start + $i*($end - $start)/$newcount), 1));
+            if ($i !== 0 and $i !== $newcount) {
+                imageline($canvas, $graph_start_x + $i*($graph_width/$newcount), $graph_start_y, $graph_start_x + $i*($graph_width/$newcount), $graph_end_y, IMG_COLOR_STYLED);
+            }
+        }
 
         // Draw title, x-axis title, y-axis title
 

From c38729572cf375686f30b96d80c421d893da13a7 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Sun, 9 Oct 2016 00:35:42 -0700
Subject: [PATCH 17/59] Draw x-axis values and grid

---
 src/Plots/Plot.php | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/src/Plots/Plot.php b/src/Plots/Plot.php
index 898f0a642..e3ec99560 100644
--- a/src/Plots/Plot.php
+++ b/src/Plots/Plot.php
@@ -88,6 +88,23 @@ public function draw($canvas)
         }
 
         // Draw title, x-axis title, y-axis title
+        $sizeTitle = 20;
+        $sizeAxis = 16;
+        if (isset($title)) {
+            $p = imagettfbbox($sizeTitle, 0, $font, $title);
+            $title_x = ($width - ($p[2] - $p[0]))/2;
+            imagettftext($canvas, $sizeTitle, $angle, $title_x, 35, $black, $font, $title);
+        }
+        if (isset($x_label)) {
+            $q = imagettfbbox($sizeAxis, 0, $font, $x_label_text);
+            $x_label_width = ($width - ($q[2] - $q[0]))/2;
+            imagettftext($canvas, $sizeAxis, $angle, $x_label_width, $height - 35, $black, $font, $x_label);
+        }
+        if (isset($x_label)) {
+            $r = imagettfbbox($sizeAxis, 90, $font, $y_label_text);
+            $y_label_height = ($height - ($r[3] - $r[1]))/2;
+            imagettftext($canvas, $sizeAxis, 90, 40, $y_label_height, $black, $font, $y_label);
+        }
 
         // Draw graph
 

From aab8930aa4c7442bc3bf954317610c1a1569155e Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Sun, 9 Oct 2016 00:40:05 -0700
Subject: [PATCH 18/59] Added section to fetch object parameters

---
 src/Plots/Plot.php | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/src/Plots/Plot.php b/src/Plots/Plot.php
index e3ec99560..9eb1fac70 100644
--- a/src/Plots/Plot.php
+++ b/src/Plots/Plot.php
@@ -9,6 +9,7 @@ public function __construct()
         parent::__construct();
         $this->x_label = "x-label";
         $this->y_label = "y-label";
+        $this->title = "Working!";
         $this->function = function ($x) { return $x; };
         $this->start = 0;
         $this->end = 10;
@@ -16,13 +17,18 @@ public function __construct()
 
     public function draw($canvas)
     {
-        // Build convenience variables for graph measures
-        $width = $this->width;
-        $height = $this->height;
+        // Grab parameters
+        $width   = $this->width;
+        $height  = $this->height;
         $padding = 50;
+        $title = $this->title;
+        $x_label = $this->x_label;
+        $y_label = $this->y_label;
+
+        // Build convenience variables for graph measures
         list($x_shift, $y_shift) = [
-            isset($this->y_label) ? 1 : 0,
-            isset($this->x_label) ? 1 : 0,
+            isset($y_label) ? 1 : 0,
+            isset($x_label) ? 1 : 0,
         ];
         list($graph_start_x, $graph_start_y, $graph_end_x, $graph_end_y) = [
             (1 + $x_shift)*$padding,
@@ -96,12 +102,12 @@ public function draw($canvas)
             imagettftext($canvas, $sizeTitle, $angle, $title_x, 35, $black, $font, $title);
         }
         if (isset($x_label)) {
-            $q = imagettfbbox($sizeAxis, 0, $font, $x_label_text);
+            $q = imagettfbbox($sizeAxis, 0, $font, $x_label);
             $x_label_width = ($width - ($q[2] - $q[0]))/2;
             imagettftext($canvas, $sizeAxis, $angle, $x_label_width, $height - 35, $black, $font, $x_label);
         }
-        if (isset($x_label)) {
-            $r = imagettfbbox($sizeAxis, 90, $font, $y_label_text);
+        if (isset($y_label)) {
+            $r = imagettfbbox($sizeAxis, 90, $font, $y_label);
             $y_label_height = ($height - ($r[3] - $r[1]))/2;
             imagettftext($canvas, $sizeAxis, 90, 40, $y_label_height, $black, $font, $y_label);
         }

From 3853e6ade3e86bf006e3fb5977917bc44f6b5033 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Sun, 9 Oct 2016 00:44:40 -0700
Subject: [PATCH 19/59] Draw graph

---
 src/Plots/Plot.php | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/Plots/Plot.php b/src/Plots/Plot.php
index 9eb1fac70..47aedec0c 100644
--- a/src/Plots/Plot.php
+++ b/src/Plots/Plot.php
@@ -10,9 +10,10 @@ public function __construct()
         $this->x_label = "x-label";
         $this->y_label = "y-label";
         $this->title = "Working!";
-        $this->function = function ($x) { return $x; };
+        $this->function = function ($x) { return sin($x); };
         $this->start = 0;
         $this->end = 10;
+        $this->weight = 3;
     }
 
     public function draw($canvas)
@@ -24,6 +25,7 @@ public function draw($canvas)
         $title = $this->title;
         $x_label = $this->x_label;
         $y_label = $this->y_label;
+        $weight  = $this->weight;
 
         // Build convenience variables for graph measures
         list($x_shift, $y_shift) = [
@@ -113,6 +115,10 @@ public function draw($canvas)
         }
 
         // Draw graph
+        imagesetthickness($canvas, $weight);
+        for ($i = 0; $i < $n; $i++) {
+            imageline($canvas, $graph_start_x + $i*$graph_step_x, $graph_start_y - ($image[$i]-$min)*$function_scale, $graph_start_x + ($i+1)*$graph_step_x, $graph_start_y - ($image[$i+1]-$min)*$function_scale, $black);
+        }
 
         return $canvas;
     }

From 47f19a22cb148681aa28186e826ddce19f06641f Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Sun, 9 Oct 2016 00:46:20 -0700
Subject: [PATCH 20/59] Moved padding to Plot class, removed canvas size from
 draw method

---
 src/Plots/Canvas.php | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/src/Plots/Canvas.php b/src/Plots/Canvas.php
index 158ee8c3d..b2f7735f8 100644
--- a/src/Plots/Canvas.php
+++ b/src/Plots/Canvas.php
@@ -16,19 +16,18 @@ public function __construct($width = 600, $height = 600)
         $this->canvas = imagecreate($width, $height);
     }
 
-    public function addPlot($padding = 0)
+    public function addPlot()
     {
-        $this->plot = new Plot($padding);
+        $this->plot = new Plot();
         return $this->plot;
     }
 
     public function save()
     {
-        $width  = $this->width;
-        $height = $this->height;
-        $canvas = imagecreate($width, $height);
+        header('Content-type: image/png');
+        $canvas = imagecreate($this->width, $this->height);
         imagecolorallocate($canvas, 255, 255, 255);
-        $canvas = $this->plot->draw($canvas, $width, $height);
+        $canvas = $this->plot->draw($canvas);
         imagejpeg($canvas, 'image-' . rand() . '.jpg');
     }
 }

From fd79f1b360fbf39964ee9740226d45ea279bab57 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Sun, 9 Oct 2016 17:26:45 -0700
Subject: [PATCH 21/59] Added grid() method

---
 src/Plots/Plot.php | 30 +++++++++++++++++-------------
 1 file changed, 17 insertions(+), 13 deletions(-)

diff --git a/src/Plots/Plot.php b/src/Plots/Plot.php
index 47aedec0c..06cae716c 100644
--- a/src/Plots/Plot.php
+++ b/src/Plots/Plot.php
@@ -4,16 +4,19 @@
 
 class Plot extends Canvas
 {
-    public function __construct()
+    public function __construct(callable $function, $start, $end)
     {
         parent::__construct();
         $this->x_label = "x-label";
-        $this->y_label = "y-label";
-        $this->title = "Working!";
-        $this->function = function ($x) { return sin($x); };
-        $this->start = 0;
-        $this->end = 10;
-        $this->weight = 3;
+        //$this->y_label = "y-label";
+        //$this->title = "Working!";
+        $this->function = $function;
+        $this->start = $start;
+        $this->end = $end;
+    }
+
+    public function grid(bool $switch) {
+        $this->grid = $switch;
     }
 
     public function draw($canvas)
@@ -22,10 +25,11 @@ public function draw($canvas)
         $width   = $this->width;
         $height  = $this->height;
         $padding = 50;
-        $title = $this->title;
-        $x_label = $this->x_label;
-        $y_label = $this->y_label;
-        $weight  = $this->weight;
+        $title   = $this->title ?? null;
+        $x_label = $this->x_label ?? null;
+        $y_label = $this->y_label ?? null;
+        $weight  = $this->weight ?? 3;
+        $grid    = $this->grid ?? false;
 
         // Build convenience variables for graph measures
         list($x_shift, $y_shift) = [
@@ -81,7 +85,7 @@ public function draw($canvas)
         imagesetstyle($canvas, $style);
         for ($i = 0; $i <= $count; $i++) {
             imagettftext($canvas, $size, $angle, $graph_start_x - $padding*0.75, $size*0.5 + $graph_start_y - $i*($graph_height/$count), $black, $font, round(($min + $i*($max - $min)/$count), 1));
-            if ($i !== 0 and $i !== $count) {
+            if ($i !== 0 and $i !== $count and $grid) {
                 imageline($canvas, $graph_start_x, $graph_start_y - $i*($graph_height/$count), $graph_end_x, $graph_start_y - $i*($graph_height/$count), IMG_COLOR_STYLED);
             }
         }
@@ -90,7 +94,7 @@ public function draw($canvas)
         $newcount = 9;
         for ($i = 0; $i <= $newcount; $i++) {
             imagettftext($canvas, $size, $angle, $graph_start_x + $i*($graph_width/$newcount), $graph_start_y + $padding/2, $black, $font, round(($start + $i*($end - $start)/$newcount), 1));
-            if ($i !== 0 and $i !== $newcount) {
+            if ($i !== 0 and $i !== $newcount and $grid) {
                 imageline($canvas, $graph_start_x + $i*($graph_width/$newcount), $graph_start_y, $graph_start_x + $i*($graph_width/$newcount), $graph_end_y, IMG_COLOR_STYLED);
             }
         }

From 16e9194469aae208396246c20a91cf1cb5dd1af3 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Sun, 9 Oct 2016 17:28:44 -0700
Subject: [PATCH 22/59] Added yLabel() method

---
 src/Plots/Plot.php | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/Plots/Plot.php b/src/Plots/Plot.php
index 06cae716c..18f11a5c5 100644
--- a/src/Plots/Plot.php
+++ b/src/Plots/Plot.php
@@ -7,7 +7,7 @@ class Plot extends Canvas
     public function __construct(callable $function, $start, $end)
     {
         parent::__construct();
-        $this->x_label = "x-label";
+        //$this->x_label = "x-label";
         //$this->y_label = "y-label";
         //$this->title = "Working!";
         $this->function = $function;
@@ -19,6 +19,10 @@ public function grid(bool $switch) {
         $this->grid = $switch;
     }
 
+    public function yLabel(string $label) {
+        $this->y_label = $label;
+    }
+
     public function draw($canvas)
     {
         // Grab parameters

From 48fb58bab4043d3ca9166678b1099ed05cfa03f4 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Sun, 9 Oct 2016 17:30:53 -0700
Subject: [PATCH 23/59] Added xLabel() method

---
 src/Plots/Plot.php | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/Plots/Plot.php b/src/Plots/Plot.php
index 18f11a5c5..cb2cc3b0b 100644
--- a/src/Plots/Plot.php
+++ b/src/Plots/Plot.php
@@ -7,9 +7,6 @@ class Plot extends Canvas
     public function __construct(callable $function, $start, $end)
     {
         parent::__construct();
-        //$this->x_label = "x-label";
-        //$this->y_label = "y-label";
-        //$this->title = "Working!";
         $this->function = $function;
         $this->start = $start;
         $this->end = $end;
@@ -23,6 +20,10 @@ public function yLabel(string $label) {
         $this->y_label = $label;
     }
 
+    public function xLabel(string $label) {
+        $this->x_label = $label;
+    }
+
     public function draw($canvas)
     {
         // Grab parameters

From 97a5661a638660e662adf0e74577557968e77f52 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Sun, 9 Oct 2016 17:33:19 -0700
Subject: [PATCH 24/59] Added title() method

---
 src/Plots/Plot.php | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/Plots/Plot.php b/src/Plots/Plot.php
index cb2cc3b0b..b5b666606 100644
--- a/src/Plots/Plot.php
+++ b/src/Plots/Plot.php
@@ -16,6 +16,10 @@ public function grid(bool $switch) {
         $this->grid = $switch;
     }
 
+    public function title(string $title) {
+        $this->title = $title;
+    }
+
     public function yLabel(string $label) {
         $this->y_label = $label;
     }
@@ -105,8 +109,8 @@ public function draw($canvas)
         }
 
         // Draw title, x-axis title, y-axis title
-        $sizeTitle = 20;
-        $sizeAxis = 16;
+        $sizeTitle = 16;
+        $sizeAxis = 14;
         if (isset($title)) {
             $p = imagettfbbox($sizeTitle, 0, $font, $title);
             $title_x = ($width - ($p[2] - $p[0]))/2;

From b92dbcb0f204aa70390fbff679f30fb3c6c15689 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Sun, 9 Oct 2016 18:14:31 -0700
Subject: [PATCH 25/59] Added color() method to Plot

---
 src/Plots/Plot.php | 40 +++++++++++++++++++++++++++++++++-------
 1 file changed, 33 insertions(+), 7 deletions(-)

diff --git a/src/Plots/Plot.php b/src/Plots/Plot.php
index b5b666606..f25e1a7ec 100644
--- a/src/Plots/Plot.php
+++ b/src/Plots/Plot.php
@@ -12,33 +12,60 @@ public function __construct(callable $function, $start, $end)
         $this->end = $end;
     }
 
-    public function grid(bool $switch) {
+    public function grid(bool $switch)
+    {
         $this->grid = $switch;
     }
 
-    public function title(string $title) {
+    public function title(string $title)
+    {
         $this->title = $title;
     }
 
-    public function yLabel(string $label) {
+    public function yLabel(string $label)
+    {
         $this->y_label = $label;
     }
 
-    public function xLabel(string $label) {
+    public function xLabel(string $label)
+    {
         $this->x_label = $label;
     }
 
+    public function color(string $color)
+    {
+        //$this->color = $color;
+        switch($color) {
+            case 'red':
+                $color = [255, 0, 0];
+                break;
+            case 'green':
+                $color = [0, 255, 0];
+                break;
+            case 'blue':
+                $color = [0, 0, 255];
+                break;
+            default:
+                $color = [0, 0, 0];
+        }
+        $this->color = $color;
+    }
+
     public function draw($canvas)
     {
+        // Set defaults
+        $black   = imagecolorallocate($canvas, 0, 0, 0);
+        $padding = 50;
+
         // Grab parameters
         $width   = $this->width;
         $height  = $this->height;
-        $padding = 50;
         $title   = $this->title ?? null;
         $x_label = $this->x_label ?? null;
         $y_label = $this->y_label ?? null;
         $weight  = $this->weight ?? 3;
         $grid    = $this->grid ?? false;
+        $color   = isset($this->color) ? imagecolorallocate($canvas, ... $this->color) : $black;
 
         // Build convenience variables for graph measures
         list($x_shift, $y_shift) = [
@@ -57,7 +84,6 @@ public function draw($canvas)
         ];
 
         // Create axes
-        $black = imagecolorallocate($canvas, 0, 0, 0);
         imagerectangle($canvas, $graph_start_x, $graph_end_y, $graph_end_x, $graph_start_y, $black);
 
         // Define input function and function domain
@@ -130,7 +156,7 @@ public function draw($canvas)
         // Draw graph
         imagesetthickness($canvas, $weight);
         for ($i = 0; $i < $n; $i++) {
-            imageline($canvas, $graph_start_x + $i*$graph_step_x, $graph_start_y - ($image[$i]-$min)*$function_scale, $graph_start_x + ($i+1)*$graph_step_x, $graph_start_y - ($image[$i+1]-$min)*$function_scale, $black);
+            imageline($canvas, $graph_start_x + $i*$graph_step_x, $graph_start_y - ($image[$i]-$min)*$function_scale, $graph_start_x + ($i+1)*$graph_step_x, $graph_start_y - ($image[$i+1]-$min)*$function_scale, $color);
         }
 
         return $canvas;

From 2b146bfe72fc22ed51379ceddd1c2ca851664e92 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Sun, 9 Oct 2016 22:04:25 -0700
Subject: [PATCH 26/59] Refactored Plot to use imagestring instead of
 imagefttext

---
 src/Plots/Plot.php | 116 +++++++++++++++++++--------------------------
 1 file changed, 48 insertions(+), 68 deletions(-)

diff --git a/src/Plots/Plot.php b/src/Plots/Plot.php
index f25e1a7ec..ef3d4f7a5 100644
--- a/src/Plots/Plot.php
+++ b/src/Plots/Plot.php
@@ -8,8 +8,8 @@ public function __construct(callable $function, $start, $end)
     {
         parent::__construct();
         $this->function = $function;
-        $this->start = $start;
-        $this->end = $end;
+        $this->start    = $start;
+        $this->end      = $end;
     }
 
     public function grid(bool $switch)
@@ -24,17 +24,16 @@ public function title(string $title)
 
     public function yLabel(string $label)
     {
-        $this->y_label = $label;
+        $this->yLabel = $label;
     }
 
     public function xLabel(string $label)
     {
-        $this->x_label = $label;
+        $this->xLabel = $label;
     }
 
     public function color(string $color)
     {
-        //$this->color = $color;
         switch($color) {
             case 'red':
                 $color = [255, 0, 0];
@@ -55,42 +54,39 @@ public function draw($canvas)
     {
         // Set defaults
         $black   = imagecolorallocate($canvas, 0, 0, 0);
+        $white   = imagecolorallocate($canvas, 255, 255, 255);
         $padding = 50;
 
         // Grab parameters
-        $width   = $this->width;
-        $height  = $this->height;
-        $title   = $this->title ?? null;
-        $x_label = $this->x_label ?? null;
-        $y_label = $this->y_label ?? null;
-        $weight  = $this->weight ?? 3;
-        $grid    = $this->grid ?? false;
-        $color   = isset($this->color) ? imagecolorallocate($canvas, ... $this->color) : $black;
-
-        // Build convenience variables for graph measures
-        list($x_shift, $y_shift) = [
-            isset($y_label) ? 1 : 0,
-            isset($x_label) ? 1 : 0,
-        ];
-        list($graph_start_x, $graph_start_y, $graph_end_x, $graph_end_y) = [
-            (1 + $x_shift)*$padding,
-            imagesy($canvas) - (1 + $y_shift)*$padding,
-            imagesx($canvas) - $padding,
-            $padding
-        ];
-        list($graph_width, $graph_height) = [
-            imagesx($canvas) - (2 + $x_shift)*$padding,
-            imagesy($canvas) - (2 + $y_shift)*$padding
-        ];
-
-        // Create axes
-        imagerectangle($canvas, $graph_start_x, $graph_end_y, $graph_end_x, $graph_start_y, $black);
-
-        // Define input function and function domain
+        $width    = $this->width;
+        $height   = $this->height;
+        $title    = $this->title ?? null;
+        $xLabel   = $this->xLabel ?? null;
+        $yLabel   = $this->yLabel ?? null;
+        $weight   = $this->weight ?? 3;
+        $grid     = $this->grid ?? false;
+        $color    = isset($this->color) ? imagecolorallocate($canvas, ... $this->color) : $black;
         $function = $this->function;
         $start    = $this->start;
         $end      = $this->end;
 
+        // Determine if we need to add padding to make room for axis labels
+        $x_shift = isset($yLabel) ? 40 : 0;
+        $y_shift = isset($xLabel) ? 10 : 0;
+
+        // Measure start and end points of plot on canvas
+        $graph_start_x = $padding + $x_shift;
+        $graph_start_y = imagesy($canvas) - ($padding + $y_shift);
+        $graph_end_x   = imagesx($canvas) - $padding;
+        $graph_end_y   = $padding;
+
+        // Measure height and width of plot on canvas
+        $graph_width  = $graph_end_x - $graph_start_x;
+        $graph_height = $graph_start_y - $graph_end_y;
+
+        // Create axes
+        imagerectangle($canvas, $graph_start_x, $graph_end_y, $graph_end_x, $graph_start_y, $black);
+
         // Calculate graph step size and function step size
         $n             = 1000;
         $graph_step_x  = $graph_width/$n;
@@ -102,55 +98,39 @@ public function draw($canvas)
         for ($i = 0; $i <= $n; $i++) {
             $image[] = $function($start + $i*$function_step);
         }
-        $min = min($image);
-        $max = max($image);
+        $min            = min($image);
+        $max            = max($image);
         $function_scale = $graph_height/($max - $min);
 
         // Draw y-axis values and grid
-        $fontpath = realpath('.'); //replace . with a different directory if needed
-        putenv('GDFONTPATH='.$fontpath);
-        $count = 9;
-        $font = 'arial.ttf';
-        $size = 10;
-        $angle = 0;
-        $length1 = 1;
-        $length2 = 5;
-        $white = imagecolorallocate($canvas, 255, 255, 255);
-        $style = array_merge(array_fill(0, $length1, $black), array_fill(0, $length2, $white));
+        $gridCountY = 10;
+        $style = array_merge(array_fill(0, 1, $black), array_fill(0, 5, $white));
         imagesetstyle($canvas, $style);
-        for ($i = 0; $i <= $count; $i++) {
-            imagettftext($canvas, $size, $angle, $graph_start_x - $padding*0.75, $size*0.5 + $graph_start_y - $i*($graph_height/$count), $black, $font, round(($min + $i*($max - $min)/$count), 1));
-            if ($i !== 0 and $i !== $count and $grid) {
-                imageline($canvas, $graph_start_x, $graph_start_y - $i*($graph_height/$count), $graph_end_x, $graph_start_y - $i*($graph_height/$count), IMG_COLOR_STYLED);
+        for ($i = 0; $i <= $gridCountY; $i++) {
+            imagestring($canvas, 2, $graph_start_x - 50, $graph_start_y - 8 - $i*($graph_height/$gridCountY), round(($min + $i*($max - $min)/$gridCountY), 1), $black);
+            if ($i !== 0 and $i !== $gridCountY and $grid) {
+                imageline($canvas, $graph_start_x, $graph_start_y - $i*($graph_height/$gridCountY), $graph_end_x, $graph_start_y - $i*($graph_height/$gridCountY), IMG_COLOR_STYLED);
             }
         }
 
         // Draw x-axis values and grid
-        $newcount = 9;
-        for ($i = 0; $i <= $newcount; $i++) {
-            imagettftext($canvas, $size, $angle, $graph_start_x + $i*($graph_width/$newcount), $graph_start_y + $padding/2, $black, $font, round(($start + $i*($end - $start)/$newcount), 1));
-            if ($i !== 0 and $i !== $newcount and $grid) {
-                imageline($canvas, $graph_start_x + $i*($graph_width/$newcount), $graph_start_y, $graph_start_x + $i*($graph_width/$newcount), $graph_end_y, IMG_COLOR_STYLED);
+        $gridCountX = 10;
+        for ($i = 0; $i <= $gridCountX; $i++) {
+            imagestring($canvas, 2, $graph_start_x + $i*($graph_width/$gridCountX), $graph_start_y + 8, round(($start + $i*($end - $start)/$gridCountX), 1), $black);
+            if ($i !== 0 and $i !== $gridCountX and $grid) {
+                imageline($canvas, $graph_start_x + $i*($graph_width/$gridCountX), $graph_start_y, $graph_start_x + $i*($graph_width/$gridCountX), $graph_end_y, IMG_COLOR_STYLED);
             }
         }
 
         // Draw title, x-axis title, y-axis title
-        $sizeTitle = 16;
-        $sizeAxis = 14;
         if (isset($title)) {
-            $p = imagettfbbox($sizeTitle, 0, $font, $title);
-            $title_x = ($width - ($p[2] - $p[0]))/2;
-            imagettftext($canvas, $sizeTitle, $angle, $title_x, 35, $black, $font, $title);
+            imagestring($canvas, 5, ($width - strlen($title)*9)/2, 18, $title, $black);
         }
-        if (isset($x_label)) {
-            $q = imagettfbbox($sizeAxis, 0, $font, $x_label);
-            $x_label_width = ($width - ($q[2] - $q[0]))/2;
-            imagettftext($canvas, $sizeAxis, $angle, $x_label_width, $height - 35, $black, $font, $x_label);
+        if (isset($xLabel)) {
+            imagestring($canvas, 4, ($width - strlen($xLabel)*8)/2, $height - 30, $xLabel, $black);
         }
-        if (isset($y_label)) {
-            $r = imagettfbbox($sizeAxis, 90, $font, $y_label);
-            $y_label_height = ($height - ($r[3] - $r[1]))/2;
-            imagettftext($canvas, $sizeAxis, 90, 40, $y_label_height, $black, $font, $y_label);
+        if (isset($yLabel)) {
+            imagestringup($canvas, 4, 10, ($height + strlen($yLabel)*8)/2, $yLabel, $black);
         }
 
         // Draw graph

From 462ad3af2ae65d563be109e4a7c4c92d5e06352e Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Sun, 9 Oct 2016 22:55:48 -0700
Subject: [PATCH 27/59] Centered axis points

---
 src/Plots/Plot.php | 32 ++++++++++++++++++++++----------
 1 file changed, 22 insertions(+), 10 deletions(-)

diff --git a/src/Plots/Plot.php b/src/Plots/Plot.php
index ef3d4f7a5..334735ff3 100644
--- a/src/Plots/Plot.php
+++ b/src/Plots/Plot.php
@@ -87,16 +87,16 @@ public function draw($canvas)
         // Create axes
         imagerectangle($canvas, $graph_start_x, $graph_end_y, $graph_end_x, $graph_start_y, $black);
 
-        // Calculate graph step size and function step size
+        // Calculate function step size (h) and graph step size
         $n             = 1000;
+        $h             = ($end - $start)/$n;
         $graph_step_x  = $graph_width/$n;
         $graph_step_y  = $graph_height/$n;
-        $function_step = ($end - $start)/$n;
 
         // Calculate function values, min, max, and function scale
         $image = [];
         for ($i = 0; $i <= $n; $i++) {
-            $image[] = $function($start + $i*$function_step);
+            $image[] = $function($start + $i*$h);
         }
         $min            = min($image);
         $max            = max($image);
@@ -107,18 +107,26 @@ public function draw($canvas)
         $style = array_merge(array_fill(0, 1, $black), array_fill(0, 5, $white));
         imagesetstyle($canvas, $style);
         for ($i = 0; $i <= $gridCountY; $i++) {
-            imagestring($canvas, 2, $graph_start_x - 50, $graph_start_y - 8 - $i*($graph_height/$gridCountY), round(($min + $i*($max - $min)/$gridCountY), 1), $black);
-            if ($i !== 0 and $i !== $gridCountY and $grid) {
-                imageline($canvas, $graph_start_x, $graph_start_y - $i*($graph_height/$gridCountY), $graph_end_x, $graph_start_y - $i*($graph_height/$gridCountY), IMG_COLOR_STYLED);
+            $value = round(($min + $i*($max - $min)/$gridCountY), 1);
+            $X₀    = $graph_start_x;
+            $Xₙ    = $graph_end_x;
+            $Y₀    = $graph_start_y - $i*($graph_height/$gridCountY);
+            imagestring($canvas, 2, $X₀ - 10 - 6*strlen($value), $Y₀ - 8, $value, $black);
+            if ($i !== 0 && $i !== $gridCountY && $grid) {
+                imageline($canvas, $X₀, $Y₀, $Xₙ, $Y₀, IMG_COLOR_STYLED);
             }
         }
 
         // Draw x-axis values and grid
         $gridCountX = 10;
         for ($i = 0; $i <= $gridCountX; $i++) {
-            imagestring($canvas, 2, $graph_start_x + $i*($graph_width/$gridCountX), $graph_start_y + 8, round(($start + $i*($end - $start)/$gridCountX), 1), $black);
-            if ($i !== 0 and $i !== $gridCountX and $grid) {
-                imageline($canvas, $graph_start_x + $i*($graph_width/$gridCountX), $graph_start_y, $graph_start_x + $i*($graph_width/$gridCountX), $graph_end_y, IMG_COLOR_STYLED);
+            $value = round(($start + $i*($end - $start)/$gridCountX), 1);
+            $X₀    = $graph_start_x + $i*($graph_width/$gridCountX);
+            $Y₀    = $graph_start_y;
+            $Yₙ    = $graph_end_y;
+            imagestring($canvas, 2, $X₀ + 2 - strlen($value)*3, $Y₀ + 8, $value, $black);
+            if ($i !== 0 && $i !== $gridCountX && $grid) {
+                imageline($canvas, $X₀, $Y₀, $X₀, $Yₙ, IMG_COLOR_STYLED);
             }
         }
 
@@ -136,7 +144,11 @@ public function draw($canvas)
         // Draw graph
         imagesetthickness($canvas, $weight);
         for ($i = 0; $i < $n; $i++) {
-            imageline($canvas, $graph_start_x + $i*$graph_step_x, $graph_start_y - ($image[$i]-$min)*$function_scale, $graph_start_x + ($i+1)*$graph_step_x, $graph_start_y - ($image[$i+1]-$min)*$function_scale, $color);
+            $xᵢ     = $graph_start_x + $i*$graph_step_x;
+            $xᵢ₊₁   = $graph_start_x + ($i+1)*$graph_step_x;
+            $f⟮xᵢ⟯   = $graph_start_y - ($image[$i]-$min)*$function_scale;
+            $f⟮xᵢ₊₁⟯ = $graph_start_y - ($image[$i+1]-$min)*$function_scale;
+            imageline($canvas, $xᵢ, $f⟮xᵢ⟯, $xᵢ₊₁, $f⟮xᵢ₊₁⟯, $color);
         }
 
         return $canvas;

From b2b95e1dc8faeb52f68565ac2ca326a2fd2c333f Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Sun, 9 Oct 2016 22:56:01 -0700
Subject: [PATCH 28/59] Centered title and axis labels

---
 src/Plots/Plot.php | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/Plots/Plot.php b/src/Plots/Plot.php
index 334735ff3..f921e8506 100644
--- a/src/Plots/Plot.php
+++ b/src/Plots/Plot.php
@@ -132,13 +132,13 @@ public function draw($canvas)
 
         // Draw title, x-axis title, y-axis title
         if (isset($title)) {
-            imagestring($canvas, 5, ($width - strlen($title)*9)/2, 18, $title, $black);
+            imagestring($canvas, 5, ($width + $x_shift - strlen($title)*9)/2, 18, $title, $black);
         }
         if (isset($xLabel)) {
-            imagestring($canvas, 4, ($width - strlen($xLabel)*8)/2, $height - 30, $xLabel, $black);
+            imagestring($canvas, 4, ($width + $x_shift - strlen($xLabel)*8)/2, $height - 30, $xLabel, $black);
         }
         if (isset($yLabel)) {
-            imagestringup($canvas, 4, 10, ($height + strlen($yLabel)*8)/2, $yLabel, $black);
+            imagestringup($canvas, 4, 10, ($height - $y_shift + strlen($yLabel)*8)/2, $yLabel, $black);
         }
 
         // Draw graph

From 5d68ad4b97698313034dd7cf023b9f77590d8d8c Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Sun, 9 Oct 2016 22:58:09 -0700
Subject: [PATCH 29/59] Centered title and axis labels

---
 src/Plots/Plot.php | 30 +++++++++++++++++-------------
 1 file changed, 17 insertions(+), 13 deletions(-)

diff --git a/src/Plots/Plot.php b/src/Plots/Plot.php
index f921e8506..73d4a6f9c 100644
--- a/src/Plots/Plot.php
+++ b/src/Plots/Plot.php
@@ -50,25 +50,29 @@ public function color(string $color)
         $this->color = $color;
     }
 
+    public function thickness(int $thickness)
+    {
+        $this->thickness = $thickness;
+    }
+
     public function draw($canvas)
     {
-        // Set defaults
         $black   = imagecolorallocate($canvas, 0, 0, 0);
         $white   = imagecolorallocate($canvas, 255, 255, 255);
         $padding = 50;
 
         // Grab parameters
-        $width    = $this->width;
-        $height   = $this->height;
-        $title    = $this->title ?? null;
-        $xLabel   = $this->xLabel ?? null;
-        $yLabel   = $this->yLabel ?? null;
-        $weight   = $this->weight ?? 3;
-        $grid     = $this->grid ?? false;
-        $color    = isset($this->color) ? imagecolorallocate($canvas, ... $this->color) : $black;
-        $function = $this->function;
-        $start    = $this->start;
-        $end      = $this->end;
+        $width     = $this->width;
+        $height    = $this->height;
+        $title     = $this->title ?? null;
+        $xLabel    = $this->xLabel ?? null;
+        $yLabel    = $this->yLabel ?? null;
+        $thickness = $this->thickness ?? 3;
+        $grid      = $this->grid ?? false;
+        $color     = isset($this->color) ? imagecolorallocate($canvas, ... $this->color) : $black;
+        $function  = $this->function;
+        $start     = $this->start;
+        $end       = $this->end;
 
         // Determine if we need to add padding to make room for axis labels
         $x_shift = isset($yLabel) ? 40 : 0;
@@ -142,7 +146,7 @@ public function draw($canvas)
         }
 
         // Draw graph
-        imagesetthickness($canvas, $weight);
+        imagesetthickness($canvas, $thickness);
         for ($i = 0; $i < $n; $i++) {
             $xᵢ     = $graph_start_x + $i*$graph_step_x;
             $xᵢ₊₁   = $graph_start_x + ($i+1)*$graph_step_x;

From ac00cd5b9cf803b81fb1c30e2b9afaf504fb9ba1 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Sun, 9 Oct 2016 23:07:27 -0700
Subject: [PATCH 30/59] Added class description for Plots

---
 src/Plots/Canvas.php | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/Plots/Canvas.php b/src/Plots/Canvas.php
index b2f7735f8..2b706224d 100644
--- a/src/Plots/Canvas.php
+++ b/src/Plots/Canvas.php
@@ -2,6 +2,11 @@
 
 namespace MathPHP\Plots;
 
+/**
+ * Plotting Canvas
+ *
+ * The base class for the plotting utility.
+ */
 class Canvas
 {
     protected $width;
@@ -16,9 +21,9 @@ public function __construct($width = 600, $height = 600)
         $this->canvas = imagecreate($width, $height);
     }
 
-    public function addPlot()
+    public function addPlot(callable $function, $start = 0, $end = 10)
     {
-        $this->plot = new Plot();
+        $this->plot = new Plot($function, $start, $end);
         return $this->plot;
     }
 

From 72888599f14c7413d52e5f45930a635058a1508a Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Sun, 9 Oct 2016 23:08:27 -0700
Subject: [PATCH 31/59] Added class description for Plots

---
 src/Plots/Canvas.php | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/Plots/Canvas.php b/src/Plots/Canvas.php
index 2b706224d..05cce0986 100644
--- a/src/Plots/Canvas.php
+++ b/src/Plots/Canvas.php
@@ -27,6 +27,12 @@ public function addPlot(callable $function, $start = 0, $end = 10)
         return $this->plot;
     }
 
+    public function size($width = 600, $height = 600)
+    {
+        $this->width  = $width;
+        $this->height = $height;
+    }
+
     public function save()
     {
         header('Content-type: image/png');

From 17a7f66018ca89d56d31ea8b3d5d20a5eb93f298 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Sun, 9 Oct 2016 23:29:29 -0700
Subject: [PATCH 32/59] Added canvas width and height into new Plot() class
 within addPlot

---
 src/Plots/Canvas.php | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/src/Plots/Canvas.php b/src/Plots/Canvas.php
index 05cce0986..b0b9f8841 100644
--- a/src/Plots/Canvas.php
+++ b/src/Plots/Canvas.php
@@ -11,19 +11,19 @@ class Canvas
 {
     protected $width;
     protected $height;
-    protected $canvas;
-    protected $plot;
+    private   $plot;
 
     public function __construct($width = 600, $height = 600)
     {
         $this->width  = $width;
         $this->height = $height;
-        $this->canvas = imagecreate($width, $height);
     }
 
     public function addPlot(callable $function, $start = 0, $end = 10)
     {
-        $this->plot = new Plot($function, $start, $end);
+        $width      = $this->width;
+        $height     = $this->height;
+        $this->plot = new Plot($function, $start, $end, $width, $height);
         return $this->plot;
     }
 
@@ -31,6 +31,9 @@ public function size($width = 600, $height = 600)
     {
         $this->width  = $width;
         $this->height = $height;
+        if(isset($this->plot)) {
+            $this->plot->size($width, $height);
+        }
     }
 
     public function save()

From 0803a194741b844b1c800e49f37696c396b70b90 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Sun, 9 Oct 2016 23:29:55 -0700
Subject: [PATCH 33/59] Added parent classes width and height into constructor

---
 src/Plots/Plot.php | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/src/Plots/Plot.php b/src/Plots/Plot.php
index 73d4a6f9c..a4de9cf8d 100644
--- a/src/Plots/Plot.php
+++ b/src/Plots/Plot.php
@@ -4,14 +4,24 @@
 
 class Plot extends Canvas
 {
-    public function __construct(callable $function, $start, $end)
+    private $function;
+    private $start;
+    private $end;
+
+    public function __construct(callable $function, $start, $end, $width, $height)
     {
-        parent::__construct();
+        parent::__construct($width, $height);
         $this->function = $function;
         $this->start    = $start;
         $this->end      = $end;
     }
 
+    public function size($width = 600, $height = 600)
+    {
+        $this->width  = $width;
+        $this->height = $height;
+    }
+
     public function grid(bool $switch)
     {
         $this->grid = $switch;

From e6fdca9ca0ed29abe1661a68ab950eb2ced3e656 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Sun, 9 Oct 2016 23:30:51 -0700
Subject: [PATCH 34/59] Added parent classes width and height into constructor

---
 src/Plots/Plot.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Plots/Plot.php b/src/Plots/Plot.php
index a4de9cf8d..d3e2989c3 100644
--- a/src/Plots/Plot.php
+++ b/src/Plots/Plot.php
@@ -16,7 +16,7 @@ public function __construct(callable $function, $start, $end, $width, $height)
         $this->end      = $end;
     }
 
-    public function size($width = 600, $height = 600)
+    public function size($width, $height)
     {
         $this->width  = $width;
         $this->height = $height;

From 9c2b0630b9d9c52a5acfb50765e476fd4b5d080c Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Sun, 9 Oct 2016 23:32:47 -0700
Subject: [PATCH 35/59] Updated default canvas size to 700 x 500

---
 src/Plots/Canvas.php | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/Plots/Canvas.php b/src/Plots/Canvas.php
index b0b9f8841..69c79389f 100644
--- a/src/Plots/Canvas.php
+++ b/src/Plots/Canvas.php
@@ -13,7 +13,7 @@ class Canvas
     protected $height;
     private   $plot;
 
-    public function __construct($width = 600, $height = 600)
+    public function __construct($width = 700, $height = 500)
     {
         $this->width  = $width;
         $this->height = $height;
@@ -27,7 +27,7 @@ public function addPlot(callable $function, $start = 0, $end = 10)
         return $this->plot;
     }
 
-    public function size($width = 600, $height = 600)
+    public function size($width, $height)
     {
         $this->width  = $width;
         $this->height = $height;

From 9e1b298217ef675c32158d9dfcf79cdf37b0d2d8 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Wed, 12 Oct 2016 22:39:41 -0700
Subject: [PATCH 36/59] Add method descriptions to Canvas class

---
 src/Plots/Canvas.php | 50 ++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 48 insertions(+), 2 deletions(-)

diff --git a/src/Plots/Canvas.php b/src/Plots/Canvas.php
index 69c79389f..6fa040c6a 100644
--- a/src/Plots/Canvas.php
+++ b/src/Plots/Canvas.php
@@ -13,21 +13,57 @@ class Canvas
     protected $height;
     private   $plot;
 
-    public function __construct($width = 700, $height = 500)
+    /**
+    * Construct a new plotting canvas.
+    *
+    * The input arguments refer to the size of the canvas in pixels. Thus,
+    * when you run the save() method, the size of the resulting image file
+    * will be determined by these parameters. For example, running
+    * (new Canvas())->save() will produce an image with a default size of
+    * 700px by 500px.
+    *
+    * @param int $width  The width of our canvas, in pixels
+    * @param int $height The height of our canvas, in pixels
+    */
+    public function __construct(int $width = 700, int $height = 500)
     {
         $this->width  = $width;
         $this->height = $height;
     }
 
+    /**
+    * Add a single plot to our canvas object.
+    *
+    * This method is used when we are including a single plot in a canvas
+    * object. To add multiple plots to a single canvas, use the addSubplot()
+    * method (to be added in a future release).
+    *
+    * @param callable $function The callback function we are plotting
+    * @param number   $start    The start of our plotting interval
+    * @param number   $end      The end of the plotting interval
+    *
+    * @return object The resulting Plot object constructed from our inputs
+    *                and the parameters of the parent canvas object
+    */
     public function addPlot(callable $function, $start = 0, $end = 10)
     {
         $width      = $this->width;
         $height     = $this->height;
         $this->plot = new Plot($function, $start, $end, $width, $height);
+
         return $this->plot;
     }
 
-    public function size($width, $height)
+    /**
+    * Modify the size of our canvas.
+    *
+    * Refer to the __construct() method for for further understanding of
+    * canvas sizes.
+    *
+    * @param int $width  The width of our canvas, in pixels
+    * @param int $height The height of our canvas, in pixels
+    */
+    public function size(int $width, int $height)
     {
         $this->width  = $width;
         $this->height = $height;
@@ -36,6 +72,16 @@ public function size($width, $height)
         }
     }
 
+    /**
+    * Draw plot(s) and output resulting canvas.
+    *
+    * Draw the plot object(s) stored within our canvas' plot parameter. Then,
+    * output the resulting canvas in a certain format. Currently, only
+    * JPG outputs are supported. More support should be added soon, such as
+    * outputting directly to a webpage, different file formats, etc.
+    *
+    * By default, this gives our canvas a white background.
+    */
     public function save()
     {
         header('Content-type: image/png');

From ea6639e809e3886db956785dc3f1d5da69b6db72 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Wed, 12 Oct 2016 22:48:14 -0700
Subject: [PATCH 37/59] Add description to Canvas Class

---
 src/Plots/Canvas.php | 25 ++++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/src/Plots/Canvas.php b/src/Plots/Canvas.php
index 6fa040c6a..7dc75d135 100644
--- a/src/Plots/Canvas.php
+++ b/src/Plots/Canvas.php
@@ -6,6 +6,22 @@
  * Plotting Canvas
  *
  * The base class for the plotting utility.
+ *
+ * This is the parent class for our plotting utility. To create a plot image,
+ * you first start with this class to build the foundation for our plot. This
+ * will create an environment for which you can add a single plot or, in the
+ * future, multiple plots.
+ *
+ * This class currently supports the following methods:
+ *   - addPlot(): add a single plot objects (graphs) to our canvas
+ *   - size():    adjust the size of our canvas
+ *   - save():    draw the current
+ *
+ * Example: Plot the graph f(x) = x over [0, 100]
+ *     $canvas = new Canvas(1000, 500);
+ *     $canvas->addPlot(function ($x) { return $x; }, 0, 100);
+ *     $canvas->save();
+ *
  */
 class Canvas
 {
@@ -38,6 +54,8 @@ public function __construct(int $width = 700, int $height = 500)
     * object. To add multiple plots to a single canvas, use the addSubplot()
     * method (to be added in a future release).
     *
+    * The default interval of our plot is [0, 10].
+    *
     * @param callable $function The callback function we are plotting
     * @param number   $start    The start of our plotting interval
     * @param number   $end      The end of the plotting interval
@@ -85,9 +103,14 @@ public function size(int $width, int $height)
     public function save()
     {
         header('Content-type: image/png');
+
         $canvas = imagecreate($this->width, $this->height);
         imagecolorallocate($canvas, 255, 255, 255);
-        $canvas = $this->plot->draw($canvas);
+
+        if (isset($this->plot)) {
+            $canvas = $this->plot->draw($canvas);
+        }
+
         imagejpeg($canvas, 'image-' . rand() . '.jpg');
     }
 }

From 2a5aabfde89f951e6cee9ac224c1c94f3663e4a4 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Wed, 12 Oct 2016 23:09:31 -0700
Subject: [PATCH 38/59] Added description to Plot class

---
 src/Plots/Plot.php | 80 +++++++++++++++++++++++++++++++++-------------
 1 file changed, 58 insertions(+), 22 deletions(-)

diff --git a/src/Plots/Plot.php b/src/Plots/Plot.php
index d3e2989c3..c7cc93ef5 100644
--- a/src/Plots/Plot.php
+++ b/src/Plots/Plot.php
@@ -2,6 +2,46 @@
 
 namespace MathPHP\Plots;
 
+/*
+* Single Plot
+*
+* Contains paramters for a single plot to draw on a parent Canvas object.
+*
+* To create a plot, first start with a canvas object. Then, construct a child
+* Plot object by using the addPlot() method in the Canvas class. This will
+* ensure that our resulting Plot object is tied to the canvas object to which
+* it corresponds. Then, we explicitly use Plot methods() for the resulting
+* plot object.
+*
+* This class currently supports the following methods:
+*   - grid(): Turn on or off the grid lines for our plot, and specify the
+*             number of grid lines for each axis
+*   - title(): Assign a title to our plot
+*   - yLabel(): Assign a label to our y-axis
+*   - xLabel(): Assign a label to our x-axis
+*   - color(): Set the color of our plot line/curve
+*   - thickness(): Set the thickness of our plot line/curve
+*
+* Example: Graph the function f(x) = x*sin(x) on [0, 20] with a grid, title,
+*          y-axis label, x-axis label, a color of red, and thickness of 5
+*     $canvas = new Canvas();
+*     $plot = $canvas->addPlot(function ($x) { return $x*sin($x); }, 0, 20);
+*     $plot->grid(true);
+*     $plot->yLabel("This is a working y-label");
+*     $plot->xLabel("Time (seconds)");
+*     $plot->title("Sample Title");
+*     $plot->color("red");
+*     $plot->thickness(5);
+*     $canvas->save();
+*
+* There are plans to add support for the following:
+*   - A method to change the font for all text
+*   - A method to change the font size for all text
+*   - A method to change the font color for all text
+*   - A method to add more graphs (functions) to the same plot
+*   - A child class for each text field (title and axis labels) which contains
+*     methods to adjust the color, size, and font of that specific text field
+*/
 class Plot extends Canvas
 {
     private $function;
@@ -16,15 +56,11 @@ public function __construct(callable $function, $start, $end, $width, $height)
         $this->end      = $end;
     }
 
-    public function size($width, $height)
+    public function grid(bool $switch = true, int $gridCountX = 10, int $gridCountY = 10)
     {
-        $this->width  = $width;
-        $this->height = $height;
-    }
-
-    public function grid(bool $switch)
-    {
-        $this->grid = $switch;
+        $this->grid       = $switch;
+        $this->gridCountX = 10;
+        $this->gridCountY = 10;
     }
 
     public function title(string $title)
@@ -71,18 +107,20 @@ public function draw($canvas)
         $white   = imagecolorallocate($canvas, 255, 255, 255);
         $padding = 50;
 
-        // Grab parameters
-        $width     = $this->width;
-        $height    = $this->height;
-        $title     = $this->title ?? null;
-        $xLabel    = $this->xLabel ?? null;
-        $yLabel    = $this->yLabel ?? null;
-        $thickness = $this->thickness ?? 3;
-        $grid      = $this->grid ?? false;
-        $color     = isset($this->color) ? imagecolorallocate($canvas, ... $this->color) : $black;
-        $function  = $this->function;
-        $start     = $this->start;
-        $end       = $this->end;
+        // Grab parameters or assign defaults
+        $width      = $this->width;
+        $height     = $this->height;
+        $title      = $this->title ?? null;
+        $xLabel     = $this->xLabel ?? null;
+        $yLabel     = $this->yLabel ?? null;
+        $color      = isset($this->color) ? imagecolorallocate($canvas, ... $this->color) : $black;
+        $thickness  = $this->thickness ?? 3;
+        $grid       = $this->grid ?? false;
+        $gridCountY = $this->gridCountY ?? 10;
+        $gridCountX = $this->gridCountX ?? 10;
+        $function   = $this->function;
+        $start      = $this->start;
+        $end        = $this->end;
 
         // Determine if we need to add padding to make room for axis labels
         $x_shift = isset($yLabel) ? 40 : 0;
@@ -117,7 +155,6 @@ public function draw($canvas)
         $function_scale = $graph_height/($max - $min);
 
         // Draw y-axis values and grid
-        $gridCountY = 10;
         $style = array_merge(array_fill(0, 1, $black), array_fill(0, 5, $white));
         imagesetstyle($canvas, $style);
         for ($i = 0; $i <= $gridCountY; $i++) {
@@ -132,7 +169,6 @@ public function draw($canvas)
         }
 
         // Draw x-axis values and grid
-        $gridCountX = 10;
         for ($i = 0; $i <= $gridCountX; $i++) {
             $value = round(($start + $i*($end - $start)/$gridCountX), 1);
             $X₀    = $graph_start_x + $i*($graph_width/$gridCountX);

From 13ae056cea9d961aba9a90e71c6cf7b5823cd164 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Wed, 12 Oct 2016 23:12:19 -0700
Subject: [PATCH 39/59] Added type checking for method outputs in Canvas class

---
 src/Plots/Canvas.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Plots/Canvas.php b/src/Plots/Canvas.php
index 7dc75d135..afbff2c13 100644
--- a/src/Plots/Canvas.php
+++ b/src/Plots/Canvas.php
@@ -63,7 +63,7 @@ public function __construct(int $width = 700, int $height = 500)
     * @return object The resulting Plot object constructed from our inputs
     *                and the parameters of the parent canvas object
     */
-    public function addPlot(callable $function, $start = 0, $end = 10)
+    public function addPlot(callable $function, $start = 0, $end = 10): Plot
     {
         $width      = $this->width;
         $height     = $this->height;

From 4a3d3fa098c10b1dd853363f55f6f0823430d356 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Wed, 12 Oct 2016 23:16:07 -0700
Subject: [PATCH 40/59] Added exception if  input in draw() is not a GD
 resource

---
 src/Plots/Plot.php | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/Plots/Plot.php b/src/Plots/Plot.php
index c7cc93ef5..cb348952d 100644
--- a/src/Plots/Plot.php
+++ b/src/Plots/Plot.php
@@ -48,7 +48,8 @@ class Plot extends Canvas
     private $start;
     private $end;
 
-    public function __construct(callable $function, $start, $end, $width, $height)
+
+    public function __construct(callable $function, float $start, float $end, int $width, int $height)
     {
         parent::__construct($width, $height);
         $this->function = $function;
@@ -103,6 +104,10 @@ public function thickness(int $thickness)
 
     public function draw($canvas)
     {
+        if (get_resource_type($canvas) !== "gd") {
+            throw new \Exception("The was an error constructing the canvas")
+        }
+
         $black   = imagecolorallocate($canvas, 0, 0, 0);
         $white   = imagecolorallocate($canvas, 255, 255, 255);
         $padding = 50;

From d8d9a0be09061960c2c9a43650ffa4cbf9552fa4 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Thu, 13 Oct 2016 01:23:32 -0700
Subject: [PATCH 41/59] Added method descriptions for Plot class

---
 src/Plots/Plot.php | 132 ++++++++++++++++++++++++++++++++++-----------
 1 file changed, 102 insertions(+), 30 deletions(-)

diff --git a/src/Plots/Plot.php b/src/Plots/Plot.php
index cb348952d..10960b799 100644
--- a/src/Plots/Plot.php
+++ b/src/Plots/Plot.php
@@ -22,7 +22,7 @@
 *   - color(): Set the color of our plot line/curve
 *   - thickness(): Set the thickness of our plot line/curve
 *
-* Example: Graph the function f(x) = x*sin(x) on [0, 20] with a grid, title,
+* Example: Plot the function f(x) = x*sin(x) on [0, 20] with a grid, title,
 *          y-axis label, x-axis label, a color of red, and thickness of 5
 *     $canvas = new Canvas();
 *     $plot = $canvas->addPlot(function ($x) { return $x*sin($x); }, 0, 20);
@@ -38,9 +38,10 @@
 *   - A method to change the font for all text
 *   - A method to change the font size for all text
 *   - A method to change the font color for all text
-*   - A method to add more graphs (functions) to the same plot
+*   - A method to add more plots (functions) to the same plot
 *   - A child class for each text field (title and axis labels) which contains
 *     methods to adjust the color, size, and font of that specific text field
+*   - A method to add a yRange to our final plot
 */
 class Plot extends Canvas
 {
@@ -48,15 +49,35 @@ class Plot extends Canvas
     private $start;
     private $end;
 
-
-    public function __construct(callable $function, float $start, float $end, int $width, int $height)
+    /**
+    * Construct a Plot object
+    *
+    * The constructed Plot object should be a child of an existing Canvas object.
+    * In the construction, we assign a callback function, and the start and end
+    * points of the interval to which we will graph the function.
+    *
+    * We should not construct a Plot object explicity (e.g. using new Plot).
+    * Rather, this constructor is accessed implicitly in the parent Canvas
+    * class, as it needs to correspond to an instance of Canvas. This is
+    * because the save() method draws our plot onto a specific instance of
+    * a GD image, and this image is initially built in the parent Canvas class.
+    */
+    public function __construct(callable $function, float $start, float $end)
     {
-        parent::__construct($width, $height);
+        parent::__construct();
         $this->function = $function;
         $this->start    = $start;
         $this->end      = $end;
     }
 
+    /**
+    * Turn the plot grid lines on or of, and specify the number of grids in
+    * each direction.
+    *
+    * @param bool $switch     A boolean for if the grid is shown or not
+    * @param int  $gridCountX The number of grid lines on the x-axis
+    * @param int  $gridCountY The number of grid lines on the y-axis
+    */
     public function grid(bool $switch = true, int $gridCountX = 10, int $gridCountY = 10)
     {
         $this->grid       = $switch;
@@ -64,21 +85,48 @@ public function grid(bool $switch = true, int $gridCountX = 10, int $gridCountY
         $this->gridCountY = 10;
     }
 
+    /**
+    * Add a title (or modify the existing one) to our plot.
+    *
+    * @param string $title The title of our plot
+    */
     public function title(string $title)
     {
         $this->title = $title;
     }
 
+    /**
+    * Add a y-axis label (or modify the existing one) to our plot.
+    *
+    * @param string $label The y-axis of our plot
+    */
     public function yLabel(string $label)
     {
         $this->yLabel = $label;
     }
 
+    /**
+    * Add a x-axis label (or modify the existing one) to our plot.
+    *
+    * @param string $label The x-axis of our plot
+    */
     public function xLabel(string $label)
     {
         $this->xLabel = $label;
     }
 
+    /**
+    * Modify the color of our plot line/curve.
+    *
+    * Input is a string which can correspond to a number of preset colors.
+    * Currently, only red, green, and blue are supported, although more colors
+    * can easily be extended.
+    *
+    * If an input string does not match a supported color, the color will
+    * default to black.
+    *
+    * @param string $color The color of our plot line/curve
+    */
     public function color(string $color)
     {
         switch($color) {
@@ -97,17 +145,41 @@ public function color(string $color)
         $this->color = $color;
     }
 
+    /**
+    * Modify the thickness of our plot line/curve.
+    *
+    * @param int $thickness The thickness of our plot line/curve
+    */
     public function thickness(int $thickness)
     {
         $this->thickness = $thickness;
     }
 
+    /**
+    * Draw the plot to our input canvas.
+    *
+    * Draw aspects of a single plot: x- and y-axis, (optional) x- and y-labels,
+    * x- and y-axis reference numbers, (optional) title, (optional) grid lines,
+    * and the actual plot itself.
+    *
+    * This method should not be called explicitly. Rather, it is accessed
+    * implicitly when you run the save() method on the parent canvas of
+    * a plot object. This ensures that a property $canvas property is
+    * created before it is passed to this method, which draws a plot onto
+    * a GD canvas.
+    *
+    * @param resource $canvas A GD resource passed in via a Canvas parent object
+    *
+    * @throws Exception if $canvas is not a GD resource
+    */
     public function draw($canvas)
     {
+        // Verify the input is a GD resource
         if (get_resource_type($canvas) !== "gd") {
-            throw new \Exception("The was an error constructing the canvas")
+            throw new \Exception("The was an error constructing the canvas");
         }
 
+        // Set convenience variables
         $black   = imagecolorallocate($canvas, 0, 0, 0);
         $white   = imagecolorallocate($canvas, 255, 255, 255);
         $padding = 50;
@@ -121,8 +193,8 @@ public function draw($canvas)
         $color      = isset($this->color) ? imagecolorallocate($canvas, ... $this->color) : $black;
         $thickness  = $this->thickness ?? 3;
         $grid       = $this->grid ?? false;
-        $gridCountY = $this->gridCountY ?? 10;
-        $gridCountX = $this->gridCountX ?? 10;
+        $gridCountY = $this->gridCountY ?? null;
+        $gridCountX = $this->gridCountX ?? null;
         $function   = $this->function;
         $start      = $this->start;
         $end        = $this->end;
@@ -132,23 +204,23 @@ public function draw($canvas)
         $y_shift = isset($xLabel) ? 10 : 0;
 
         // Measure start and end points of plot on canvas
-        $graph_start_x = $padding + $x_shift;
-        $graph_start_y = imagesy($canvas) - ($padding + $y_shift);
-        $graph_end_x   = imagesx($canvas) - $padding;
-        $graph_end_y   = $padding;
+        $plot_start_x = $padding + $x_shift;
+        $plot_start_y = imagesy($canvas) - ($padding + $y_shift);
+        $plot_end_x   = imagesx($canvas) - $padding;
+        $plot_end_y   = $padding;
 
         // Measure height and width of plot on canvas
-        $graph_width  = $graph_end_x - $graph_start_x;
-        $graph_height = $graph_start_y - $graph_end_y;
+        $plot_width  = $plot_end_x - $plot_start_x;
+        $plot_height = $plot_start_y - $plot_end_y;
 
         // Create axes
-        imagerectangle($canvas, $graph_start_x, $graph_end_y, $graph_end_x, $graph_start_y, $black);
+        imagerectangle($canvas, $plot_start_x, $plot_end_y, $plot_end_x, $plot_start_y, $black);
 
-        // Calculate function step size (h) and graph step size
+        // Calculate function step size (h) and plot step size
         $n             = 1000;
         $h             = ($end - $start)/$n;
-        $graph_step_x  = $graph_width/$n;
-        $graph_step_y  = $graph_height/$n;
+        $plot_step_x   = $plot_width/$n;
+        $plot_step_y   = $plot_height/$n;
 
         // Calculate function values, min, max, and function scale
         $image = [];
@@ -157,16 +229,16 @@ public function draw($canvas)
         }
         $min            = min($image);
         $max            = max($image);
-        $function_scale = $graph_height/($max - $min);
+        $function_scale = $plot_height/($max - $min);
 
         // Draw y-axis values and grid
         $style = array_merge(array_fill(0, 1, $black), array_fill(0, 5, $white));
         imagesetstyle($canvas, $style);
         for ($i = 0; $i <= $gridCountY; $i++) {
             $value = round(($min + $i*($max - $min)/$gridCountY), 1);
-            $X₀    = $graph_start_x;
-            $Xₙ    = $graph_end_x;
-            $Y₀    = $graph_start_y - $i*($graph_height/$gridCountY);
+            $X₀    = $plot_start_x;
+            $Xₙ    = $plot_end_x;
+            $Y₀    = $plot_start_y - $i*($plot_height/$gridCountY);
             imagestring($canvas, 2, $X₀ - 10 - 6*strlen($value), $Y₀ - 8, $value, $black);
             if ($i !== 0 && $i !== $gridCountY && $grid) {
                 imageline($canvas, $X₀, $Y₀, $Xₙ, $Y₀, IMG_COLOR_STYLED);
@@ -176,9 +248,9 @@ public function draw($canvas)
         // Draw x-axis values and grid
         for ($i = 0; $i <= $gridCountX; $i++) {
             $value = round(($start + $i*($end - $start)/$gridCountX), 1);
-            $X₀    = $graph_start_x + $i*($graph_width/$gridCountX);
-            $Y₀    = $graph_start_y;
-            $Yₙ    = $graph_end_y;
+            $X₀    = $plot_start_x + $i*($plot_width/$gridCountX);
+            $Y₀    = $plot_start_y;
+            $Yₙ    = $plot_end_y;
             imagestring($canvas, 2, $X₀ + 2 - strlen($value)*3, $Y₀ + 8, $value, $black);
             if ($i !== 0 && $i !== $gridCountX && $grid) {
                 imageline($canvas, $X₀, $Y₀, $X₀, $Yₙ, IMG_COLOR_STYLED);
@@ -196,13 +268,13 @@ public function draw($canvas)
             imagestringup($canvas, 4, 10, ($height - $y_shift + strlen($yLabel)*8)/2, $yLabel, $black);
         }
 
-        // Draw graph
+        // Draw plot
         imagesetthickness($canvas, $thickness);
         for ($i = 0; $i < $n; $i++) {
-            $xᵢ     = $graph_start_x + $i*$graph_step_x;
-            $xᵢ₊₁   = $graph_start_x + ($i+1)*$graph_step_x;
-            $f⟮xᵢ⟯   = $graph_start_y - ($image[$i]-$min)*$function_scale;
-            $f⟮xᵢ₊₁⟯ = $graph_start_y - ($image[$i+1]-$min)*$function_scale;
+            $xᵢ     = $plot_start_x + $i*$plot_step_x;
+            $xᵢ₊₁   = $plot_start_x + ($i+1)*$plot_step_x;
+            $f⟮xᵢ⟯   = $plot_start_y - ($image[$i]-$min)*$function_scale;
+            $f⟮xᵢ₊₁⟯ = $plot_start_y - ($image[$i+1]-$min)*$function_scale;
             imageline($canvas, $xᵢ, $f⟮xᵢ⟯, $xᵢ₊₁, $f⟮xᵢ₊₁⟯, $color);
         }
 

From c28cde54feaaed0eb8d819abb3b855c994d8acdc Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Thu, 13 Oct 2016 01:25:59 -0700
Subject: [PATCH 42/59] Added xRange() method to Plot class

---
 src/Plots/Plot.php | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/src/Plots/Plot.php b/src/Plots/Plot.php
index 10960b799..acef35a76 100644
--- a/src/Plots/Plot.php
+++ b/src/Plots/Plot.php
@@ -61,6 +61,10 @@ class Plot extends Canvas
     * class, as it needs to correspond to an instance of Canvas. This is
     * because the save() method draws our plot onto a specific instance of
     * a GD image, and this image is initially built in the parent Canvas class.
+    *
+    * @param callable $function The callback function we are plotting
+    * @param number   $start    The start of our plotting interval
+    * @param number   $end      The end of the plotting interval
     */
     public function __construct(callable $function, float $start, float $end)
     {
@@ -70,6 +74,19 @@ public function __construct(callable $function, float $start, float $end)
         $this->end      = $end;
     }
 
+    /**
+    * Ajust the start and endpoint of the interval to which we are plotting
+    * a function.
+    *
+    * @param number $start    The start of our plotting interval
+    * @param number $end      The end of the plotting interval
+    */
+    public function xRange(float $start, float $end)
+    {
+        $this->start = $start;
+        $this->end   = $end;
+    }
+
     /**
     * Turn the plot grid lines on or of, and specify the number of grids in
     * each direction.

From c56feb748dde847c24b3a69f3f9a90ee4d05b1f5 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Thu, 13 Oct 2016 01:32:08 -0700
Subject: [PATCH 43/59] Added conditional statements and exception to validate
 start and end inputs

---
 src/Plots/Plot.php | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/src/Plots/Plot.php b/src/Plots/Plot.php
index acef35a76..5b2005345 100644
--- a/src/Plots/Plot.php
+++ b/src/Plots/Plot.php
@@ -65,11 +65,28 @@ class Plot extends Canvas
     * @param callable $function The callback function we are plotting
     * @param number   $start    The start of our plotting interval
     * @param number   $end      The end of the plotting interval
+    *
+    * @throws Exception if $start = $end (not an interval, just a point)
     */
     public function __construct(callable $function, float $start, float $end)
     {
         parent::__construct();
+
         $this->function = $function;
+
+        if ($start === $end) {
+            throw new \Exception("Start and end points the interval of our
+                                  graph cannot be the same. Your current input
+                                  would produce a graph over the interval
+                                  [{$start}, {$end}], which is just a single
+                                  point");
+        }
+
+        // Swap variables if start point is greater than end point
+        if ($start > $end) {
+            list($start, $end) = [$end, $start];
+        }
+
         $this->start    = $start;
         $this->end      = $end;
     }

From e6683f38ee6a7512f5c1fcce05733cafcf9df0fe Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Thu, 13 Oct 2016 01:37:44 -0700
Subject: [PATCH 44/59] Moved the interval validation as a sharable component
 in the Canvas class

---
 src/Plots/Canvas.php | 25 +++++++++++++++++++++++++
 src/Plots/Plot.php   | 20 +++-----------------
 2 files changed, 28 insertions(+), 17 deletions(-)

diff --git a/src/Plots/Canvas.php b/src/Plots/Canvas.php
index afbff2c13..cd0419697 100644
--- a/src/Plots/Canvas.php
+++ b/src/Plots/Canvas.php
@@ -113,4 +113,29 @@ public function save()
 
         imagejpeg($canvas, 'image-' . rand() . '.jpg');
     }
+
+    /**
+    * Valide that our input is a proper interval (not just a point).
+    *
+    * If the start point is greater than the input, swap the variables.
+    *
+    * @throws Exception if $start = $end (not an interval, just a point)
+    */
+    public function validateInterval(int $start, int $end)
+    {
+        if ($start === $end) {
+            throw new \Exception("Start and end points the interval of our
+                                  graph cannot be the same. Your current input
+                                  would produce a graph over the interval
+                                  [{$start}, {$end}], which is just a single
+                                  point");
+        }
+
+        // Swap variables if start point is greater than end point
+        if ($start > $end) {
+            list($start, $end) = [$end, $start];
+        }
+
+        return [$start, $end];
+    }
 }
diff --git a/src/Plots/Plot.php b/src/Plots/Plot.php
index 5b2005345..684dc0943 100644
--- a/src/Plots/Plot.php
+++ b/src/Plots/Plot.php
@@ -65,8 +65,6 @@ class Plot extends Canvas
     * @param callable $function The callback function we are plotting
     * @param number   $start    The start of our plotting interval
     * @param number   $end      The end of the plotting interval
-    *
-    * @throws Exception if $start = $end (not an interval, just a point)
     */
     public function __construct(callable $function, float $start, float $end)
     {
@@ -74,21 +72,9 @@ public function __construct(callable $function, float $start, float $end)
 
         $this->function = $function;
 
-        if ($start === $end) {
-            throw new \Exception("Start and end points the interval of our
-                                  graph cannot be the same. Your current input
-                                  would produce a graph over the interval
-                                  [{$start}, {$end}], which is just a single
-                                  point");
-        }
-
-        // Swap variables if start point is greater than end point
-        if ($start > $end) {
-            list($start, $end) = [$end, $start];
-        }
-
-        $this->start    = $start;
-        $this->end      = $end;
+        list($start, $end) = $this->validateInterval($start, $end);
+        $this->start       = $start;
+        $this->end         = $end;
     }
 
     /**

From 6ee3bff539585472e080e72cbd11d62f32e300b5 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Thu, 13 Oct 2016 01:46:07 -0700
Subject: [PATCH 45/59] Added Exception to grid() method if either grid line
 count is negative

---
 src/Plots/Plot.php | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/src/Plots/Plot.php b/src/Plots/Plot.php
index 684dc0943..8b2cb7187 100644
--- a/src/Plots/Plot.php
+++ b/src/Plots/Plot.php
@@ -68,11 +68,11 @@ class Plot extends Canvas
     */
     public function __construct(callable $function, float $start, float $end)
     {
-        parent::__construct();
+        list($start, $end) = $this->validateInterval($start, $end);
 
-        $this->function = $function;
+        parent::__construct();
 
-        list($start, $end) = $this->validateInterval($start, $end);
+        $this->function    = $function;
         $this->start       = $start;
         $this->end         = $end;
     }
@@ -86,6 +86,8 @@ public function __construct(callable $function, float $start, float $end)
     */
     public function xRange(float $start, float $end)
     {
+        list($start, $end) = $this->validateInterval($start, $end);
+
         $this->start = $start;
         $this->end   = $end;
     }
@@ -97,9 +99,15 @@ public function xRange(float $start, float $end)
     * @param bool $switch     A boolean for if the grid is shown or not
     * @param int  $gridCountX The number of grid lines on the x-axis
     * @param int  $gridCountY The number of grid lines on the y-axis
+    *
+    * @throws Exception if $gridCountX or $gridCountY is negative
     */
     public function grid(bool $switch = true, int $gridCountX = 10, int $gridCountY = 10)
     {
+        if ($gridCountX < 0 || $gridCountY < 0) {
+            throw new \Exception("Number of grid lines cannot be negative");
+        }
+
         $this->grid       = $switch;
         $this->gridCountX = 10;
         $this->gridCountY = 10;
@@ -162,6 +170,7 @@ public function color(string $color)
             default:
                 $color = [0, 0, 0];
         }
+
         $this->color = $color;
     }
 

From 77a5d37a07b4a29673e9c9e8f70a178f4d14c8d3 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Thu, 13 Oct 2016 02:16:40 -0700
Subject: [PATCH 46/59] Added validateSize() method to Canvas

---
 src/Plots/Canvas.php | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/src/Plots/Canvas.php b/src/Plots/Canvas.php
index cd0419697..ca01e8937 100644
--- a/src/Plots/Canvas.php
+++ b/src/Plots/Canvas.php
@@ -43,6 +43,8 @@ class Canvas
     */
     public function __construct(int $width = 700, int $height = 500)
     {
+        $this->validateSize($width, $height);
+
         $this->width  = $width;
         $this->height = $height;
     }
@@ -67,7 +69,9 @@ public function addPlot(callable $function, $start = 0, $end = 10): Plot
     {
         $width      = $this->width;
         $height     = $this->height;
-        $this->plot = new Plot($function, $start, $end, $width, $height);
+
+        list($start, $end) = $this->validateInterval($start, $end);
+        $this->plot        = new Plot($function, $start, $end, $width, $height);
 
         return $this->plot;
     }
@@ -83,8 +87,12 @@ public function addPlot(callable $function, $start = 0, $end = 10): Plot
     */
     public function size(int $width, int $height)
     {
+        $this->validateSize($width, $height);
+
         $this->width  = $width;
         $this->height = $height;
+
+        // If we've already added a plot to the canvas, adjust it's size as well
         if(isset($this->plot)) {
             $this->plot->size($width, $height);
         }
@@ -114,6 +122,18 @@ public function save()
         imagejpeg($canvas, 'image-' . rand() . '.jpg');
     }
 
+    /**
+    * Validate the input size of our canvus
+    *
+    * @throws Exception if $width or $height is negative
+    */
+    public function validateSize(int $width, int $height)
+    {
+        if ($width < 0 || $height < 0) {
+            throw new \Exception("Canvas dimensions cannot be negative");
+        }
+    }
+
     /**
     * Valide that our input is a proper interval (not just a point).
     *

From 81e9fef1498fff731312a56ed8bf541b92a8b247 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Thu, 13 Oct 2016 02:17:32 -0700
Subject: [PATCH 47/59] Added Exception if  input is negative

---
 src/Plots/Plot.php | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/Plots/Plot.php b/src/Plots/Plot.php
index 8b2cb7187..db43efe94 100644
--- a/src/Plots/Plot.php
+++ b/src/Plots/Plot.php
@@ -178,9 +178,15 @@ public function color(string $color)
     * Modify the thickness of our plot line/curve.
     *
     * @param int $thickness The thickness of our plot line/curve
+    *
+    * @throws Exception if $thickness is negative
     */
     public function thickness(int $thickness)
     {
+        if ($thickness < 0) {
+            throw new \Exception("Thickness cannot be negative");
+        }
+
         $this->thickness = $thickness;
     }
 

From f41612a7e1cc3727f4ac545a6959494e30866c23 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Thu, 13 Oct 2016 02:24:06 -0700
Subject: [PATCH 48/59] Added test for Plots class

---
 tests/Plots/CanvasTest.php | 8 ++++++++
 1 file changed, 8 insertions(+)
 create mode 100644 tests/Plots/CanvasTest.php

diff --git a/tests/Plots/CanvasTest.php b/tests/Plots/CanvasTest.php
new file mode 100644
index 000000000..1ddea3dc6
--- /dev/null
+++ b/tests/Plots/CanvasTest.php
@@ -0,0 +1,8 @@
+<?php
+
+namespace MathPHP\Plots;
+
+class CanvasTest extends \PHPUnit_Framework_TestCase
+{
+
+}

From df279f42ae176182edb6a436f877b01c08e9043d Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Thu, 13 Oct 2016 02:24:25 -0700
Subject: [PATCH 49/59] Added test to Plots for validateSize() exceptions

---
 tests/Plots/CanvasTest.php | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/tests/Plots/CanvasTest.php b/tests/Plots/CanvasTest.php
index 1ddea3dc6..5ae0a6b2d 100644
--- a/tests/Plots/CanvasTest.php
+++ b/tests/Plots/CanvasTest.php
@@ -4,5 +4,15 @@
 
 class CanvasTest extends \PHPUnit_Framework_TestCase
 {
+    public function testValidateSizeException()
+    {
+        // Giving a negative size for canvas dimensions
+        $this->setExpectedException('\Exception');
+        new Canvas(-100, 500);
 
+        // Adjust to a negative size for canvas dimensions
+        $this->setExpectedException('\Exception');
+        $canvas = new Canvas();
+        $canvas->size(-100, 500);
+    }
 }

From f5143e20e9fcba85d6233507d0e4595f851b9c5c Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Thu, 13 Oct 2016 02:26:09 -0700
Subject: [PATCH 50/59] Added test to Canvas for validateInterval() Exceptions

---
 tests/Plots/CanvasTest.php | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/tests/Plots/CanvasTest.php b/tests/Plots/CanvasTest.php
index 5ae0a6b2d..be45fb6b6 100644
--- a/tests/Plots/CanvasTest.php
+++ b/tests/Plots/CanvasTest.php
@@ -15,4 +15,18 @@ public function testValidateSizeException()
         $canvas = new Canvas();
         $canvas->size(-100, 500);
     }
+
+    public function testValidateInterval()
+    {
+        // The input interval is set to single point (start = end)
+        $this->setExpectedException('\Exception');
+        $canvas = new Canvas();
+        $canvas->addPlot(function ($x) { return 1; }, 0, 0);
+
+        // The plot interval is adjusted to single point (start = end)
+        $this->setExpectedException('\Exception');
+        $canvas = new Canvas();
+        $plot = $canvas->addPlot(function ($x) { return 1; }, 0, 10);
+        $plot->xRange(10, 10);
+    }
 }

From 8635ec5b03ebcfae1f407c422b88de85a94983d3 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Thu, 13 Oct 2016 02:27:35 -0700
Subject: [PATCH 51/59] Added additional tests for validateSize() exceptions

---
 tests/Plots/CanvasTest.php | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/tests/Plots/CanvasTest.php b/tests/Plots/CanvasTest.php
index be45fb6b6..7a3a18aec 100644
--- a/tests/Plots/CanvasTest.php
+++ b/tests/Plots/CanvasTest.php
@@ -10,6 +10,12 @@ public function testValidateSizeException()
         $this->setExpectedException('\Exception');
         new Canvas(-100, 500);
 
+        $this->setExpectedException('\Exception');
+        new Canvas(100, -500);
+
+        $this->setExpectedException('\Exception');
+        new Canvas(-100, -500);
+
         // Adjust to a negative size for canvas dimensions
         $this->setExpectedException('\Exception');
         $canvas = new Canvas();

From c120d76d6839ac65336e7067cb243ad5a2b5bab5 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Thu, 13 Oct 2016 02:30:09 -0700
Subject: [PATCH 52/59] Split exception tests so there is only one exception in
 each

---
 tests/Plots/CanvasTest.php | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/tests/Plots/CanvasTest.php b/tests/Plots/CanvasTest.php
index 7a3a18aec..67e1e47cc 100644
--- a/tests/Plots/CanvasTest.php
+++ b/tests/Plots/CanvasTest.php
@@ -4,31 +4,31 @@
 
 class CanvasTest extends \PHPUnit_Framework_TestCase
 {
-    public function testValidateSizeException()
+    public function testValidateSizeExceptionSet()
     {
         // Giving a negative size for canvas dimensions
         $this->setExpectedException('\Exception');
         new Canvas(-100, 500);
+    }
 
-        $this->setExpectedException('\Exception');
-        new Canvas(100, -500);
-
-        $this->setExpectedException('\Exception');
-        new Canvas(-100, -500);
-
+    public function testValidateSizeExceptionUpdate()
+    {
         // Adjust to a negative size for canvas dimensions
         $this->setExpectedException('\Exception');
         $canvas = new Canvas();
         $canvas->size(-100, 500);
     }
 
-    public function testValidateInterval()
+    public function testValidateIntervalSet()
     {
         // The input interval is set to single point (start = end)
         $this->setExpectedException('\Exception');
         $canvas = new Canvas();
         $canvas->addPlot(function ($x) { return 1; }, 0, 0);
+    }
 
+    public function testValidateIntervalUpdate()
+    {
         // The plot interval is adjusted to single point (start = end)
         $this->setExpectedException('\Exception');
         $canvas = new Canvas();

From 2942c9791246beb0b2f63cc575f43783c78875d0 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Thu, 13 Oct 2016 02:31:45 -0700
Subject: [PATCH 53/59] Added test for Plot Class

---
 tests/Plots/PlotTest.php | 8 ++++++++
 1 file changed, 8 insertions(+)
 create mode 100644 tests/Plots/PlotTest.php

diff --git a/tests/Plots/PlotTest.php b/tests/Plots/PlotTest.php
new file mode 100644
index 000000000..523f47b94
--- /dev/null
+++ b/tests/Plots/PlotTest.php
@@ -0,0 +1,8 @@
+<?php
+
+namespace MathPHP\Plots;
+
+class PlotTest extends \PHPUnit_Framework_TestCase
+{
+
+}

From 62e4513c1b70e8d5caae4f8c410a7a39f1a45796 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Thu, 13 Oct 2016 02:31:57 -0700
Subject: [PATCH 54/59] Added test for grid exception

---
 tests/Plots/PlotTest.php | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/tests/Plots/PlotTest.php b/tests/Plots/PlotTest.php
index 523f47b94..8bb016b7e 100644
--- a/tests/Plots/PlotTest.php
+++ b/tests/Plots/PlotTest.php
@@ -4,5 +4,12 @@
 
 class PlotTest extends \PHPUnit_Framework_TestCase
 {
-
+    public function testGridException()
+    {
+        // Giving a negative number
+        $this->setExpectedException('\Exception');
+        $canvas = new Canvas();
+        $plot = $canvas->addPlot(function ($x) { return 1; }, 0, 10);
+        $plot->grid(true, -10, 5);
+    }
 }

From b7acb7d5e2c3f1ad8792185dbac16d153382b2a3 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Thu, 13 Oct 2016 02:32:08 -0700
Subject: [PATCH 55/59] Added test for thickness exception

---
 tests/Plots/PlotTest.php | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/tests/Plots/PlotTest.php b/tests/Plots/PlotTest.php
index 8bb016b7e..c2b357ba0 100644
--- a/tests/Plots/PlotTest.php
+++ b/tests/Plots/PlotTest.php
@@ -12,4 +12,13 @@ public function testGridException()
         $plot = $canvas->addPlot(function ($x) { return 1; }, 0, 10);
         $plot->grid(true, -10, 5);
     }
+
+    public function testThicknessException()
+    {
+        // Giving a negative number
+        $this->setExpectedException('\Exception');
+        $canvas = new Canvas();
+        $plot = $canvas->addPlot(function ($x) { return 1; }, 0, 10);
+        $plot->thickness(-10);
+    }
 }

From 60795b25325eaca688c4e6158153e9b8243f4e31 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Thu, 13 Oct 2016 02:36:45 -0700
Subject: [PATCH 56/59] Added test for Plot() Exception

---
 tests/Plots/PlotTest.php | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/tests/Plots/PlotTest.php b/tests/Plots/PlotTest.php
index c2b357ba0..9fc4d88be 100644
--- a/tests/Plots/PlotTest.php
+++ b/tests/Plots/PlotTest.php
@@ -21,4 +21,14 @@ public function testThicknessException()
         $plot = $canvas->addPlot(function ($x) { return 1; }, 0, 10);
         $plot->thickness(-10);
     }
+
+    public function testPlotException()
+    {
+        // Giving a $canvas input which is not a GD resource
+        $not_a_gd_resource = "this is a string, not a GD resource";
+        $this->setExpectedException('\Exception');
+        $canvas = new Canvas();
+        $plot = $canvas->addPlot(function ($x) { return 1; }, 0, 10);
+        $plot->draw($not_a_gd_resource);
+    }
 }

From 96e3a0e72dd9db9eb9a1dbfc5f81f614fffbb661 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Thu, 13 Oct 2016 02:37:09 -0700
Subject: [PATCH 57/59] Added catch to ensure  is a resource before checking
 its type

---
 src/Plots/Plot.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/Plots/Plot.php b/src/Plots/Plot.php
index db43efe94..1c79527c9 100644
--- a/src/Plots/Plot.php
+++ b/src/Plots/Plot.php
@@ -210,7 +210,7 @@ public function thickness(int $thickness)
     public function draw($canvas)
     {
         // Verify the input is a GD resource
-        if (get_resource_type($canvas) !== "gd") {
+        if (!(is_resource($canvas) && get_resource_type($canvas) === "gd")) {
             throw new \Exception("The was an error constructing the canvas");
         }
 

From 22061668409bde749f3d33566069bca2efe63a46 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Thu, 13 Oct 2016 02:43:54 -0700
Subject: [PATCH 58/59] PSR

---
 src/Plots/Canvas.php       |  4 ++--
 src/Plots/Plot.php         |  2 +-
 tests/Plots/CanvasTest.php | 10 ++++++++--
 tests/Plots/PlotTest.php   | 16 +++++++++++++---
 4 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/src/Plots/Canvas.php b/src/Plots/Canvas.php
index ca01e8937..df3fd2cd6 100644
--- a/src/Plots/Canvas.php
+++ b/src/Plots/Canvas.php
@@ -27,7 +27,7 @@ class Canvas
 {
     protected $width;
     protected $height;
-    private   $plot;
+    private $plot;
 
     /**
     * Construct a new plotting canvas.
@@ -93,7 +93,7 @@ public function size(int $width, int $height)
         $this->height = $height;
 
         // If we've already added a plot to the canvas, adjust it's size as well
-        if(isset($this->plot)) {
+        if (isset($this->plot)) {
             $this->plot->size($width, $height);
         }
     }
diff --git a/src/Plots/Plot.php b/src/Plots/Plot.php
index 1c79527c9..4a1eecdb8 100644
--- a/src/Plots/Plot.php
+++ b/src/Plots/Plot.php
@@ -157,7 +157,7 @@ public function xLabel(string $label)
     */
     public function color(string $color)
     {
-        switch($color) {
+        switch ($color) {
             case 'red':
                 $color = [255, 0, 0];
                 break;
diff --git a/tests/Plots/CanvasTest.php b/tests/Plots/CanvasTest.php
index 67e1e47cc..dd9a15dfe 100644
--- a/tests/Plots/CanvasTest.php
+++ b/tests/Plots/CanvasTest.php
@@ -24,7 +24,10 @@ public function testValidateIntervalSet()
         // The input interval is set to single point (start = end)
         $this->setExpectedException('\Exception');
         $canvas = new Canvas();
-        $canvas->addPlot(function ($x) { return 1; }, 0, 0);
+        $function = function ($x) {
+            return 1;
+        };
+        $canvas->addPlot($function, 0, 0);
     }
 
     public function testValidateIntervalUpdate()
@@ -32,7 +35,10 @@ public function testValidateIntervalUpdate()
         // The plot interval is adjusted to single point (start = end)
         $this->setExpectedException('\Exception');
         $canvas = new Canvas();
-        $plot = $canvas->addPlot(function ($x) { return 1; }, 0, 10);
+        $function = function ($x) {
+            return 1;
+        };
+        $canvas->addPlot($function, 0, 10);
         $plot->xRange(10, 10);
     }
 }
diff --git a/tests/Plots/PlotTest.php b/tests/Plots/PlotTest.php
index 9fc4d88be..3cbe04e03 100644
--- a/tests/Plots/PlotTest.php
+++ b/tests/Plots/PlotTest.php
@@ -9,7 +9,11 @@ public function testGridException()
         // Giving a negative number
         $this->setExpectedException('\Exception');
         $canvas = new Canvas();
-        $plot = $canvas->addPlot(function ($x) { return 1; }, 0, 10);
+        $function = function ($x) {
+            return 1;
+        };
+        $canvas->addPlot($function, 0, 0);
+        $plot = $canvas->addPlot($function, 0, 10);
         $plot->grid(true, -10, 5);
     }
 
@@ -18,7 +22,10 @@ public function testThicknessException()
         // Giving a negative number
         $this->setExpectedException('\Exception');
         $canvas = new Canvas();
-        $plot = $canvas->addPlot(function ($x) { return 1; }, 0, 10);
+        $function = function ($x) {
+            return 1;
+        };
+        $plot = $canvas->addPlot($function, 0, 10);
         $plot->thickness(-10);
     }
 
@@ -28,7 +35,10 @@ public function testPlotException()
         $not_a_gd_resource = "this is a string, not a GD resource";
         $this->setExpectedException('\Exception');
         $canvas = new Canvas();
-        $plot = $canvas->addPlot(function ($x) { return 1; }, 0, 10);
+        $function = function ($x) {
+            return 1;
+        };
+        $plot = $canvas->addPlot($function, 0, 10);
         $plot->draw($not_a_gd_resource);
     }
 }

From 3e1bba472f6e18920901cc592bf98e2519f9b638 Mon Sep 17 00:00:00 2001
From: jakobsandberg <jakobsandberg95@gmail.com>
Date: Thu, 13 Oct 2016 03:20:25 -0700
Subject: [PATCH 59/59] Added catch if GD extension is not loaded

---
 src/Plots/Canvas.php | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/Plots/Canvas.php b/src/Plots/Canvas.php
index df3fd2cd6..0d1208bb0 100644
--- a/src/Plots/Canvas.php
+++ b/src/Plots/Canvas.php
@@ -43,6 +43,14 @@ class Canvas
     */
     public function __construct(int $width = 700, int $height = 500)
     {
+        if (!extension_loaded('gd')) {
+            if (!dl('gd.so')) {
+                echo "GD extension is not installed/loaded. Ensure it is setup
+                      property and then try again";
+                exit;
+            }
+        }
+
         $this->validateSize($width, $height);
 
         $this->width  = $width;