[GRASS-dev] Speed map display in wxGUI on bigger monitors

Michael Barton Michael.Barton at asu.edu
Mon Aug 13 16:13:37 PDT 2012

I just checked this. I have an iMac with a 27" screen, which is pretty large and high res. (max of 1440 rows x 2560 cols)

default on open: 546 rows x 798 cols = 435708 
full screen: 1303 rows x 2036 cols = 2652908 pixels

The color shaded relief map (d.shade) took about 2 seconds to render at full screen.

If I constrain display resolution to match the raster file it goes a bit faster because the raster resolution is not high. If it had high raster res, it would be the other way around.

One thing I *have* noticed recently is that a large number of vector objects (e.g., LiDAR points) can take a long time to render. But this is a function of d.vect rendering of many objects, irrespective of resolution or size of temp display file.

C. Michael Barton 
Director, Center for Social Dynamics & Complexity
Professor of Anthropology, School of Human Evolution & Social Change
Arizona State University
Tempe, AZ  85287-2402

voice: 	480-965-6262 (SHESC), 480-727-9746 (CSDC)
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www: 	http://csdc.asu.edu, http://shesc.asu.edu

On Aug 13, 2012, at 3:33 PM, Markus Neteler wrote:

> On Mon, Aug 13, 2012 at 9:17 PM, Michael Barton <Michael.Barton at asu.edu> wrote:
>> The size of the monitor shouldn't have much (or anything in most cases) to
>> do with this.
> Please try on a big monitor - I am pretty sure it does.
>> Important questions:
>> Which version is being used?
> GRASS 7.svn
>> Which OS
> Fedora 17, 64bit.
>> How is the display set? If it is set to constrain display resolution to
>> match map, this could happen. However, the default behavior for a long time
>> is to create display output at display resolution (depends on the size of
>> the display window). Even with big monitors, this is not a huge file by
>> GRASS GIS standards. However, the temp files that are created for the
>> displays will be larger when larger windows are used on larger monitors
>> (i.e., more pixels to render).
> I observe that files in the multi-megabyte range are generated in this case.
> Hence it is getting slow...
> Markus

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