[GRASS-user] GRASS7.4 TGRASS parse error while mapcalc computatio

[Martin Landa]

Hi,

2018-02-21 12:57 GMT+01:00 Anika Bettge <bettge at mundialis.de>:
> I use TGRASS to calculate a NDVI.

btw, recently I was doing something similar in Jena GRASS GIS workshop, see [1].

> GRASS 7.4.0 (accra32630):~ > t.rast.mapcalc input=b4,b8 output=test1
> expression="test1 = float(b8 + b4)" basename=test1  --overwrite
> Starting temporal sampling...
> Starting mapcalc computation...
> Ungültige Karte
> <S2_0e76f09b_d221_4e88_b7f9_d3S2_0e76f09b_d221_4e88_b7f9_d3b8aad4975d_20180102T140217_B08_10maad4975d_20180102T140217_B04_10m>
> Parse error
> FEHLER: parse error
> ERROR: Error while mapcalc computation

It seems like your input strds are broken. Try to check all maps
registered in input b4 and b8 datasets (by t.rast.list).
t.rast.mapcalc tries to read non-existing raster map
S2_0e76f09b_d221_4e88_b7f9_d3S2_0e76f09b_d221_4e88_b7f9_d3b8aad4975d_20180102T140217_B08_10maad4975d_20180102T140217_B04_10m
in your case.

Ma

[1] http://training.gismentors.eu/grass-gis-workshop-jena-2018/units/21.html#ndvi-st-computation

-- 
Martin Landa
http://geo.fsv.cvut.cz/gwiki/Landa
http://gismentors.cz/mentors/landa