[GRASS-user] r.mapcalc help on eliminating negative values

[Luisa Peña]

Greetings

I'm having some unexpected difficulties on setting negative valeus to null
using r.mapcalc.

I have a raster named d_data (DCELL) with  the following range of values
 |   Range of data:    min = -0.001399  max = 0.356480
Only a few values are negative so I want to set them to null

I have used this expression
if(d_cell at National <0 , null(), d_cell at National)
and when i do r.info output I get:
|   Data Type:    DCELL
 |   Range of data:    min = nan  max = nan

Which is not expected

What am I doing wrong in this expression?

Thanks
Luisa
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