[GRASS-user] r.regression.multi for logistic regression - it is possible?

[Roberto Marzocchi]

 Dear all,

I have dichotomous data (occurrence 1 and non-occurence 0) and I want to
use the  logistic regression method in order to obtain susceptibility map
of landslide occurrence.

I try to use r.regression.multi, but I am not sure to correctly define the
mapy variable..

I try to use r.mapcalc

*r.mapcalc
expression="logit_occurrence=log(occurrence_map+0.00001)-log(1-occurrence_map+0.00001)"*

obtaining a map that go from -11.5 (not occurrence) to +11.5 (occurrence)

when I try to use r.regression.multi I obtain a lot of null values in
residuals and estimates map.

i do not understand why..

Thanks in advanced for the attention
Roberto
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