Grass 6/7

[KittelC]

It seems QGIS 2.18 no longer works with GRASS 6, however quite a few of the scripts use grass:r.mapcalculator, which is not supported by GRASS 7. Is there an alternative or work-around? Specifically, the climate data download workflows no longer work (e.g. GetECMFWClimateData etc.)...

[radosuav]

GRASS 6 should work in QGIS 2.18 but it is disabled by default. It needs to be activated in Processing > Options > Providers > GRASS commands. This should be taken care of if using the WOIS installer.

In the longer term (QGIS 3.x) GRASS 6 will no longer be supported. Possible workarounds would be to use OTB band math , GDAL raster calculator or (new in QGIS 3.x) Processing raster calculator.

[KittelC]

I have activated GRASS 6 (and checked it is installed) but I keep receiving an error message about GRASS not being installed properly when I try to run any GRASS 6 algorithm.. It seems like it is included but does not function.

[radosuav]

This usually indicates that GRASS paths are not set properly. Double check that the path set in Processing > Options > Providers > GRASS Commands > GRASS folder is correct. For example if you recently updated from GRASS 6.4.2 to 6.4.3 then this path needs to be modified.

[KittelC]

I have double checked the paths (including the msys path), but nothing seems to work (I also get a different error message than when something is up with the paths..) - I have tried to update and reinstall GRASS 6 (and gone back to GRASS 6.4.2) without success... I've been using a numpy array approach instead for the ECMWF calculation which also works faster than mapcalculator, but it is really strange that GRASS 6 just doesn't work..

[ctottrup]

and the GRASS 6 desktop application starts up with no problem?

[j08lue]

This usually indicates that GRASS paths are not set properly.

That would be my guess, too.

But you say it looks similar to this, @KittelC?

[KittelC]

Yes, mine is identical to this @j08lue @ctottrup - this might be the issue - when I try to run GRASS 6, I get a System Error: "gdal110.dll is missing from your computer. Try reinstalling the program to fix this problem". @radosuav this joins what you were writing in the other thread - that gdal might be the source of problem.

[KittelC]

I installed gdal110dll through advanced installation of OSGeo4w, and now the GRASS processing seems to work. It seems to have been a backwards compatibility issue, which is not automatically installed with OSGeo4w.

[j08lue]

https://github.com/TIGER-NET/WOIS_Installer/issues/26

[j08lue]

It seems like installing gdal110dll fixes the problem, @KittelC!

I am checking some more installations to be all sure.

[j08lue]

Fixes the problem with WOIS package v4.2 on Windows 32 bit.

[j08lue]

And also on Windows 64 bit.