[QGIS-Developer] Raster calculator problems

[kozskan at seznam.cz]

Dear All,



I am dealing with raster calculator issue and I am not quite sure about the 
algorithm of this tool, it seems that it somehow does not work in way I 
would liked to. I discussed this issue on GIS stackexchange and people 
assumed that the sytax is correct. The version of QGIS I am using is 3.8.0.,
also I've tried to use previous releases but none worked.




The thing is that I have a 1-band geotif raster and I use following syntax 
in order to create output raster where values from the 1-band raster 
represents following table. In other words, I have a raster layer with 
values ranging from 0.00597303 to 0.102894 and I want to assign specific 
number representing a group to specific range of values:



 Group 4: x >= 0.1



Group 3: 0.01 <= x < 0.1

Group 2: x < 0.01

I am using the following syntax: 

("Ri_Q50 at 1" >= 0.1) * 4 + (("Ri_Q50 at 1" >= 0.01) AND ("Ri_Q50 at 1" < 0.1)) * 3 
+ ("Ri_Q50 at 1" < 0.01) * 2




But the output is not quite what I am looking for - I think that raster 
calculator should be suitable to do this job.




I don't know what else could be the problem then my unsufficient knowladge 
of the algorithm of raster calculator.




I would be very greatful for any kind of advice.

Thank you very much for help, I appreciate that.

Kind regards

Václav
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