Can't load layers from previous session

[JacobusS]

I ran a buffer on a very large raster, but forgot to write out the layer using the writeRaster() function before I closed R.
I setup is as follows:
faster(
grassDir = "C:/Program Files/GRASS GIS 8.4",
workDir = "C:/GRASS_DB"
)

But every session creates a new sub directory within C:/GRASS_DB, in my case the sub folder is Hartebeesthoek94_DxfSjjIWGILH with a grass raster called "buffer_BGOyE84BGB0S"
This is great but how do now create a new gRaster R object that points to "buffer_BGOyE84BGB0S"

I can open grass gui and get the layer, but in future it would be nice to list all the layers in a project and then create a gRaster object in R.
Maybe I'm missing something, so please correct me if that's the case.

Great library by the way, it's absolutely increasable.

[adamlilith]

Good question! I anticipated most users would only want to use fasterRaster like they would terra and not bother with GRASS files directly. However, there is a way to do this, though I can't guarantee it would work in all cases. There is a hidden function called makeGRaster() that creates GRasters from GRASS files. You just need to know the GRASS file name, which it sounds like you have. So, I think in your case, you'd use:

new_graster <- fasterRaster:::makeGRaster('C:/GRASS_DB/buffer_BGOyE84BGB0S')

Before this, you'd have to use faster() like you do above to do the setup, of course, and then create any kind of GRaster or GVector so that GRASS actually started in the background.

You need to use the ::: syntax because it's a hidden function. You can also get help on the function using fasterRaster:::makeGRaster? The levels and ac arguments are only for categorical rasters, which it sounds like is not your case. In case you would need it, there is also a makeGVector() function.

Good luck--as I said, I had not anticipated users wanting to interact directly with GRASS files, so I didn't build direct user support for this, but maybe I should.

-A