[GRASS-user] Training map error. missing classes

[Nikos Alexandris]

Nathaniel Iwuchukwu:
>                 i am getting an error when i run the i.gensigset on
>                 the training map i created and the trainig map is
>                 blank after i perform vector to raster. 
>                 this is what i typed and the result:
>                 
>                 GRASS 6.4.0RC5 (sis):~/Desktop > i.gensigset
>                 trainingmap=traingis group=sislabgp subgroup=sislabsub
>                 signaturefile=sislab.sig
>                 Finding training classes...
>                  100%
>                 ERROR: Training map has no classes 
>                 does snyone have any clue why i don't have classes in
>                 my training map? 
>           
>                 what should i do. thanks


Some pointers:

- check the training map again (it's a raster, right?)

- what does "r.cats traingis" say?

- check that the raster maps for which you want to create signatures, do
not contain NULL-pixels at your defined training areas ( I remember
having a problem with this).

- check that your defined areas in the training map are not too small
(e.g. they should be >17pix)

Nikos