[GRASS-user] Re: Command to summarize the frequency distribution table

[Yasuo SHIMADA]

Dear Glynn: 

thank you good advice.

> Reclass maps only work for integers

I see, I understood the cause from your advice.

> Alternatively, if the intervals are equally spaced, you could generate
> an integer version by scaling, e.g.:
> 
> 	r.mapcalc 'newmap = int(oldmap * 10)'
> 

r.mapcalc has a wonderful function, I think.

Okey,it's a nice method. I'll try again. 

Thank you. 

Yasuo SHIMADA
--
> SGW00412 at nifty.com wrote:
> 
> > Thank you useful and kind advice.
> > Sorry, please give advice to me a little more.
> > 
> > I tried the re-classification by using r.reclass method in the raster map of the
> > probability distribution.
> 
> > I want to classify it at 0.1 intervals. So I wrote text files as follows:
> > -----------
> > 0.0 thru 0.1=0 A
> > 0.1 thru 0.2=2 B
> > 0.3 thru 0.4=3 C
> > 0.4 thru 0.5=4 D
> >  ....
> > 0.9 thru 1.0=10 J
> > end
> > -----------
> > 
> > then, I saved as probability_class.txt
> > 
> > r.reclass input=old_rast_map output=new_rast_map < probability_class.txt
> > 
> > then,  following massage printed out on display:
> > -----
> > 0.500000 rounded up to 0
> > 0.600000 rounded up to 0
> 
> > Why ? What's happened ?
> > I do not understand the cause not appropriately classified.
> 
> Reclass maps only work for integers (they are implemented by looking
> up the original cell values in an array, and you can't use
> floating-point values as array indices).
> 
> You can use r.recode to generate a new map using a piecewise-linear
> mapping. The category labels need to be set separately using
> r.category.
> 
> Alternatively, if the intervals are equally spaced, you could generate
> an integer version by scaling, e.g.:
> 
> 	r.mapcalc 'newmap = int(oldmap * 10)'
>