partdiff

partdiff is an application to solve partial differential equations using the Gauß-Seidel and Jacobi methods.

It is mainly used for teaching and research purposes.

partdiff was originally created by Thomas Ludwig, Thomas A. Zochler, and Andreas C. Schmidt in Fortran and has since been ported to C.

Usage

$ git clone https://github.com/parcio/partdiff.git
$ cd partdiff
$ make
$ ./partdiff
Usage: ./partdiff [num] [method] [lines] [func] [term] [acc/iter]

  - num:       number of threads (1 .. 1024)
  - method:    calculation method (1 .. 2)
                 1: Gauß-Seidel
                 2: Jacobi
  - lines:     number of interlines (0 .. 100000)
                 matrixsize = (interlines * 8) + 9
  - func:      perturbation function (1 .. 2)
                 1: f(x,y) = 0
                 2: f(x,y) = 2 * pi^2 * sin(pi * x) * sin(pi * y)
  - term:      termination condition (1 .. 2)
                 1: sufficient accuracy
                 2: number of iterations
  - acc/iter:  depending on term:
                 accuracy:   1e-4 .. 1e-20
                 iterations:    1 .. 200000

Example: ./partdiff 1 2 100 1 2 100

$ ./partdiff 1 2 100 1 2 100
Calculation time:       0.082096 s
Memory usage:           9.986588 MiB
Calculation method:     Jacobi
Interlines:             100
Perturbation function:  f(x,y) = 0
Termination:            Number of iterations
Number of iterations:   100
Residuum:               3.544251e-03

Matrix:
 1.0000 0.8750 0.7500 0.6250 0.5000 0.3750 0.2500 0.1250 0.0000
 0.8750 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.1250
 0.7500 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.2500
 0.6250 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.3750
 0.5000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.5000
 0.3750 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.6250
 0.2500 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.7500
 0.1250 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.8750
 0.0000 0.1250 0.2500 0.3750 0.5000 0.6250 0.7500 0.8750 1.0000

Regression testing

We use partdiff_tester to perform automatic regression tests.

Other Implementations

Here is a list of some partdiff implementations in other languages that we're aware of:

Implementation	Programming Language
mblesel/rust_partdiff	Rust
felsenhower/partdiffpp	C++
felsenhower/partdiff-py	Python