[GRASS-dev] wxpython gui: speed of display

[Glynn Clements]

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.

-- 
Glynn Clements <glynn at gclements.plus.com>