[GRASS-dev] wxpython gui: speed of display

[Michael Barton]

Glynn,

What's the difference between

GRASS_PNG_AUTO_WRITE and GRASS_RENDER_IMMEDIATE?

Isn't there also a flag on each d.command to have it output directly to a
PNG/PPM file without runing d.mon?

Michael

__________________________________________
Michael Barton, Professor of Anthropology
School of Human Evolution & Social Change
Center for Social Dynamics and Complexity
Arizona State University

phone: 480-965-6213
fax: 480-965-7671
www: http://www.public.asu.edu/~cmbarton


> From: Moritz Lennert <mlennert at club.worldonline.be>
> Date: Thu, 17 Aug 2006 00:44:32 +0200 (CEST)
> To: Glynn Clements <glynn at gclements.plus.com>
> Cc: Michael Barton <michael.barton at asu.edu>, Grass Developers List
> <grass-dev at grass.itc.it>
> Subject: Re: [GRASS-dev] wxpython gui: speed of display
> 
> On Wed, August 16, 2006 16:13, Glynn Clements wrote:
>> 
>> Moritz Lennert wrote:
>> 
>>> While we are working on a new wxpython prototype, I would like to
>>> mention raise the issue of speed of display (which is also valid for
>>> gis.m).
>>> 
>>> When I display a vector map with 65961 boundaries and 20464 areas, it
>>> takes about 10 seconds to display it with type=area and fcol=none (ca
>>> 13s with no parameters set). In ArcView under Windows this takes only
>>> max 3s.
>>> 
>>> I was wondering where the difference comes from. Is it the passage
>>> through g.composite ? Is it the fact that we are not dealing with simple
>>> features ? Something else ?
>> 
>> It's unlikely to be related to g.pnmcomp. For a start, the time taken
>> by g.pnmcomp depends only on the size and number of the images being
>> composited, not the contents of the images.
>> 
>> It's more likely that most of the time is taken by d.vect. Try running
>> d.vect directly (using the PNG driver), and timing that. Also, try
>> using GRASS_RENDER_IMMEDIATE=TRUE to see if that makes a noticeable
>> difference.
> 
> It halves the rendering time:
> 
> GRASS 6.3.cvs (BELGIQUE):~ > echo $GRASS_RENDER_IMMEDIATE
> FALSE
> GRASS 6.3.cvs (BELGIQUE):~ > d.mon start=PNG
> PNG: GRASS_TRUECOLOR status: FALSE
> PNG: collecting to file: map.png,
>      GRASS_WIDTH=640, GRASS_HEIGHT=480
> Graphics driver [PNG] started
> GRASS 6.3.cvs (BELGIQUE):~ > date;d.vect ssbel01 fcol=none type=area;date
> jeudi 17 août 2006, 00:35:08 (UTC+0200)
> jeudi 17 août 2006, 00:35:14 (UTC+0200)
> GRASS 6.3.cvs (BELGIQUE):~ > d.mon stop=PNG
> Monitor 'PNG' terminated
> GRASS 6.3.cvs (BELGIQUE):~ > export GRASS_RENDER_IMMEDIATE=TRUE
> GRASS 6.3.cvs (BELGIQUE):~ > date;d.vect ssbel01 fcol=none type=area;date
> jeudi 17 août 2006, 00:35:29 (UTC+0200)
> PNG: GRASS_TRUECOLOR status: FALSE
> PNG: collecting to file: map.png,
>      GRASS_WIDTH=640, GRASS_HEIGHT=480
> jeudi 17 août 2006, 00:35:32 (UTC+0200)
> 
> How could I test this with the wxpython gui ?
> 
> Moritz
> 
> P.S. I won't be around for a week. So I'll have to wait for the end of
> next week to test this more.
>