[GRASS-user] GUI freeze when trying to change legend

[Michael Denslow]

Hi Markus,

>> Dear Grass,
>>
>> I am having a problem when I try to change the legend for my raster
>> file using to GUI. This happens even if I select a new legend to add.
>> As soon as I select the raster map from the list Grass freezes for
>> several minutes.
>>
>> Perhaps it is a problem with the raster file or the rules file,
>> however it runs fine when I run the command in the terminal. I would
>> like to do this in the GUI since I am not sure how to do all of my map
>> resizing and saving as .tif from the command line.
>>
>> Can someone please advise me on this?
>>
>> I am using Grass 6.4 with standard GUI (not Python)
>> System is Mac OS 10.6.1
>
> Hi Michael.
>
> idea:
> a problem could be that the color table of the map has more than 8000
> entries. In that case the X Window system becomes very slow.
>
> Suggestion: make a copy of the map (g.copy) and apply a gyr colortable
> or likewise to see if the behaviour changes. If not, the problem is elsewhere
> and to be investigated. If yes, you may post more details about the map
> in order to suggest an optimized color table.
>
> Markus
>

I did what you suggested (g.copy of raster, r.color with gyr). The
color table was actually already set to gyr so the map looked
essentially the same and it also took 5 or so minutes to load the
legend file as before.

About the file:
The raster file is a reclassed raster with 7 or so categories that it
based off of the elev_state_500m file from the North Carolina dataset.
I did some r.mapcalc on the original raster and then reclassed it. It
is a large file and r.stats and r.report also take several minutes to
compute. Is it possible that the slowness is cause by it being a big
file? Also I read somewhere in your book about making a copy of a
reclassed raster so that it does not depend on the original file
(can't find the page right now!). Is this suggested?

The only thing is that the legend command does run fast when put
through the command line...

Bottom line, all is working in the GUI just very slow.
Thanks for your quick response,
Michael



-- 
Michael Denslow

Graduate Student
I.W. Carpenter Jr. Herbarium [BOON]
Department of Biology
Appalachian State University
Boone, North Carolina U.S.A.

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