[GRASSLIST:526] Re: e00 import, creating reclass from dig-cats file (was: creating legend file for vector map)

[Keith J. Forbes]

On Wednesday 25 June 2003 09:39, Moritz Lennert wrote:
> Hi Keith,
> (cc to the grass-users list, so that other can profit from our discussions
> ;-) )
>
> Keith J. Forbes said:
> > Dear Moritz:
> >
> > Thanks for sticking with this.
> >
> > Ok. something is weird here and I think it has to do with the original
> > import of the e00 file (source of the data). I copied the attached file
> > to ecol, and then ran v.support.
> >
> > I checked with v.info, and the other r ones, as you suggested, and there
> > are 547 cats not 43. Now, each of these cats which from the file created
> > in dig_cats is basically a different ecotype. I would like each ecotype
> > to appear as a unique color and in the legend.
>
> GRASS texts can be a bit confusing in there use of the terms category and
> attribute: the attribute or category NUMBER is stored in the dig_att file,
> the LABELS (i.e. the descriptions) for the different attributes or
> categories are stored in the dig_cats file.
>
> So, when your file is imported, a dig_att file is created with
> category/attribute numbers, that don't necessarily have to be unique.
> Here's an example of the contents of such a file:
>
> A 163027.7718230 151474.5355770          1
> A 164207.9674190 172255.2677390          2
> A 189804.7270340 238558.1220960          3
> A 190347.9399790 238476.2118820          3
>
> It is this file that is used for the definition of the categories in the
> raster file. So if you have a dig_att file containing 547 different
> category numbers, then v.to.rast will give you 547 different categories in
> the resulting categories file.
>
> m.in.e00 creates different dig_cats files for each seperate attribute it
> finds in the e00 file. You correctly identified the one you're interested
> in and copied it to ecol, but this concerns the labels or descriptions,
> not the category numbers which are unique for each polygon.
>
> > I tried fooling GRASS by
> > creating a text file with columns as follows:
> >
> >
> > (normal header info)
> >
> > 1:ecotype1
> > 1:ecotype1
> > 2:ecotype2
> > 2:ecotype2
> > 2:ecotype2
> > 3:ecotype3
> > 3:ecotype3
> > and so on for all 547
> >
> > and then running v.support
> >
> > GRASS did not like this at all.
>
> The numbers on the left should be unique and correspond to the numbers
> used in the dig_att file, so it is normal that this doesn't work.
>
> > So, I am going to try r.reclass on the raster file, and, after changing
> > all values to zero, change all the values for the same ecotype to the
> > same number (from 2-43). Then, I will run d.legend to see if it works.
>
> You need to use the dig_cats file to create reclass rules in order to make
> your category labels into category numbers. See
> http://op.gfz-potsdam.de/GRASS-List/Archive/msg08631.html for two
> different solutions to this. However, as far as I can see, only the second
> (the one in the cited section of the mail) will work if your labels in the
> dig_cats file are text (as is your cas). But I might be wrong.
>
> I hope this will solve your problems.
>
> Moritz

Moritz: Hi again.
Tried the second method as you suggested from  
http://op.gfz-potsdam.de/GRASS-List/Archive/msg08631.html
worked like a charm.

One question though. This process with the awk script and then using the file 
with a unique identifier for each label as follows as the basis for v.reclass 
and then v.support, would this be a much faster equivalent of a manual 
interactive v.reclass or r.reclass, changing the value to the same unique 
number for each label, and then running v.support? 
--------
1=1 label1
2=1 label1
3=2 label2
4=2 label2
5=2 label2
to
547 (in this case)


and so on for all the "categories" created by GRASS during m.in.e00 import of 
e00 file in a particular label file (in dig_cats directory)


Decided to get the GRASS book by Mitasova et al.!! My questions may be less 
easy in the future. ;)
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k|J|f