[GRASS-user] Raster classification by typical methods?

[Timmie]

> Those two are equivalent. And can be done with a little r.mapcalc math 
> or with r.recode rules (which you can embed in a script if you need to 
> calculate the intervals on the fly.
What is the reason for not having this implemented in GRASS directly?
Design considerations?

I am looking for raster classification in equvalents to 
* Equal Interval
* Quantile (OK, see below)
* Natural Breaks (Jenks)
* Standard Deviation
* Pretty Breaks

Note: OSGEO4W does not install R.

> > * automatically classification based on defined number of classes
> 
> You can use r.quantile for quantile classification:
 
> r.quantile elevation quantiles=5 -r --quiet | r.recode elevation 
> out=elev_quant5 rules=-
How do I get "|" pipe in the GUI on OSGEO4W?

I got a strange output using the example from the handbook:

r.quantile -r --q input=RASTER_fullrange percentiles=0.2,0.4,0.6,0.8
900.000000:900.000000:1
900.000000:900.000000:2
900.000000:900.000000:3
900.000000:900.000000:4
900.000000:2000.000000:5

What is wrong here?

And when I use the quanitles I get anther strange:

r.quantile -r --quiet input=RASTER_fullrange quantiles=4
1120.000000:1120.000000:1
2120.000000:1340.000000:2
1340.000000:1560.000000:3
1560.000000:2000.000000:4

-> Why does ot not set class 1 to
900.000000:1120.000000:1

900 is the minimum value.

Thanks a lot in advance,
Timmie