i.cluster / GRASS 5.0beta

Stephan Eickschen eicksch
Tue Mar 16 04:20:26 EST 1999


Hi everybody-

I have problems with i.cluster. I want to perform a unsupervized radio-
metric classification of some passive microwave images. I have success-
fully imported them into GRASS5.0beta. I created a group and a subgroup
containing four of the seven channels - each has *no* NULL or 0 values
in the region set with g.region. There is *no* mask set. g.region
reports:

> Mapset <EkstroemisenHR> in Location <Antarctica>
> GRASS 5.0beta > g.region -p
> projection: 0 (x,y)
> zone:       0
> north:      2250000
> south:      1800000
> east:       -100000
> west:       -550000
> nsres:      3125
> ewres:      3125
> rows:       144
> cols:       144

But all I get is:

> GRASS 5.0beta > i.cluster group=f13_ndc_9701XX_1200
>       subgroup=f13_ndc_9701XX_1200 sigfile=f13_ndc_9701XX_1200.txt
>       classes=4
> Reading image ...  100%
> ERROR: Not enough non-zero sample data points. Check your current
> region
>       (and mask)

The "source-images" are in the mapset PERMANENT not in the current
"working" one; they have an x-y resolution of 12500 x 12500:

> Mapset <PERMANENT> in Location <Antarctica>
> GRASS 5.0beta > g.region -p
> projection: 0 (x,y)
> zone:       0
> north:      4350000
> south:      -3950000
> east:       3950000
> west:       -3950000
> nsres:      12500
> ewres:      12500
> rows:       664
> cols:       632

Does this matter?

Thanks in advance for any hint,

        Stephan
-- 
------------------------------------------------------------------------

Stephan Eickschen                     Tel. : +49 (0)251 83-34704
Westfaelische Wilhelms-Universitaet   Fax. : +49 (0)251 83-36100
Institute for Geophysics
Research Unit of Physical Glaciology  email: eicksch at uni-muenster.de
Corrensstrasse 24
48149 Muenster
Germany
		http://earth.uni-muenster.de/~eicksch/
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