[GRASS-dev] Re: windows binaries

[Moritz Lennert]

Michael Barton wrote:
> Disclaimer: I only see a fragment of the entire post, and might
> misunderstand.
> 
> D.vect.thematic does not require any particular driver. It uses d.vect
> (iterated over different theme values) to render the final map.
> 
> This is why it can work with either an xmonitor or a TclTk canvas (the
> latter via the PNG driver and immediate rendering mode.)

It won't work in immediate rendering mode since, as you say, it calls 
d.vect several times and in immediate rendering mode each call creates a 
new map from scratch, thus losing the overlaying of the different 
classes. This is why, in order to make it work with gis.m, it is (as far 
as I know) the only module using the PNG driver, and not immediate 
rendering. However, the PNG driver is not available in wingrass.

> D.vect.thematic should become a C-module like d.vect.chart. But since I
> don't know C I simply wish.

It is high on my priority list as it will be a convincing argument for 
my colleagues if I can present them a nice module for thematic mapping.

Up to now, I was thinking neither in terms of ps.map, nor in terms of 
d.graph, but rather in terms of direct access to rendering. In my 
current understanding this means finding out how d.vect works in detail 
and applying that to d.vect.thematic.

But maybe using do_poly() and do_color() from d.graph might be another 
solution, but I will have to look at these in detail to understand.

I think I will try to quite quickly draw up a description of what I am 
aiming for and then ask y'all to advise me at how to do it.

Moritz

> 
> Michael
> __________________________________________
> Michael Barton, Professor of Anthropology
> School of Human Evolution & Social Change
> Center for Social Dynamics & Complexity
> Arizona State University
> 
> phone: 480-965-6213
> fax: 480-965-7671
> www: http://www.public.asu.edu/~cmbarton
> 
> 
> 
>> From: Hamish <hamish_nospam at yahoo.com>
>> Date: Wed, 8 Nov 2006 16:05:19 +1300
>> To: Paul Kelly <paul-grass at stjohnspoint.co.uk>
>> Cc: <grass-dev at grass.itc.it>
>> Subject: Re: [GRASS-dev] Re: windows binaries
>>
>> Paul Kelly wrote:
>>> Didn't I read that d.vect.thematic needs the PNG driver to work. Have
>>> to  confess that I'm not sure what it does - could it use ps.map?
>> d.graph would be an easier path I think.
>>
>>
>> Hamish
>>
>>
> 
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