[GRASS5] testing GRASS5.0.0pre1

[mberglund]

On Fri, 20 Apr 2001, Markus Neteler wrote:

> Seems we need some test pattern (to get comparable results):
> As r.mapcalc is my friend, what about (in a huge location):
>
>  r.mapcalc testA="if(row()%2., row(), null())"
>  r.mapcalc testB="if(col()%2., col(), null())"
>
>
> Fre Apr 20 11:30:48 CEST 2001
> r.patch: percent complete: 100%
> CREATING SUPPORT FILES FOR testpatch
> Fre Apr 20 11:31:40 CEST 2001
Test 1:

Fri Apr 20 09:37:05 EDT 2001
r.patch: percent complete:  100%
CREATING SUPPORT FILES FOR testpatch
Fri Apr 20 09:39:36 EDT 2001

Yes, your machine is about 3 time faster than mine (stands to reason).

I am working on test two, but it is going to take a while.

Now, this is interesting. I have a color table of only 1 entry, for each
of the input files (on my original data) and for my category files.

COLRS:
matt at europa:~/GIS/maps/marion/sp/colr > cat 4117se1
% 0 16581375
0:0 16581375:255
matt at europa:~/GIS/maps/marion/sp/colr > cat marion
% 0 16581375
0:0 16581375:255


CATS:
matt at europa:~/GIS/maps/marion/sp/cats > cat 4117se1
# 16581375 categories


0.00 0.00 0.00 0.00
matt at europa:~/GIS/maps/marion/sp/cats > cat marion
# 16581375 categories


0.00 0.00 0.00 0.00

But in the patch I had a 830KB cat file! The color file was also large.

> Perhaps above test should be extended with some r.colors stuff to assign
> more colors (to get a larger color table). Note: It is well known that
> GRASS becomes *very* slow with more than 8000 entries in color table.

Is grass also slow to create the colors? And does it stand to reason that
a larger number of categories implys a larger color palete.

I ran r.support on the patch file before this conversation, so the only
thing I can tell you is that the color file was big, and the categories
file was 830KB.

When I import my tiffs (using r.in.gdal) I have to run r.support to get
the grey scaled image I require. When I give it the color count, am I
giving it too many colors to work with? I am working from 24 bit tiffs.

Thanks for all the help, as soon as I am done with test 2, I'll pipe up.

Thanks,
Matt


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