November 14, 2019

Getting started with the Grass GIS

I can start grass from the command line via "grass76", but this is unfortunate and likely to change as new versions come out. My system pulldown offers a way to start it under "Education". I downloaded their North Carolina sample dataset (145M) as nc_spm_08_grass7.tar.gz.

They recommend creating a directory like "grassdata" in your home directory. I will put this on a different large disk as /u1/Grassdata. Once this is done, you create projects as "locations" within that directory.

I untar the sample data into /u1/Grassdata and it becomes /u1/Grassdata/nc_spm_08_grass7. Then when I "browse" to /u1/Grassdata, it discovers this location and offers to let me start a Grass session on it. This launches two GUI, a layer manager and a map display. But I get errors like: 

(wxgui.py:17015): Gtk-CRITICAL **: 18:18:04.821: gtk_box_gadget_distribute: assertion 'size >= 0' failed in GtkScrollbar
And I get nothing of use in the displays. I try "grass76 -tcltk" based on some stuff on the website, but this yields all manner of error messages. I can type "grass76 -text" and get a command prompt from grass, but this looks like something you would need to be an expert to do anything with.

Move on to version 7.8

I get the same error. Maybe I should try QGIS instead of Grass.
Have any comments? Questions? Drop me a line!

Tom's GIS pages / tom@mmto.org