[R-sig-Geo] How to test for a layer in GRASS GIS mapset using rgrass7

[Rich Shepard]

On Tue, 4 Dec 2018, Christian Willmes wrote:

> During my script I use r.mapcalc from GRASS GIS to do some expensive
> computation. So I want to store and reuse the resulting layer, wich is
> produced according to a variable value, in case I need this layer for the
> specific variable value again.
>
> If I just omit the overwrite tag it does not work, becasue GRASS GIS stops 
> the execution on this event.

Christian,

   Yes, grass wants the --o flag to overwrite an existing file. You can learn
what raster maps exist using 'g.list type=rast | grep <mapname>'.

HTH,

Rich