[GRASS5] data set of world countries unique centroids

Moritz Lennert mlennert at club.worldonline.be
Sun Dec 12 09:43:29 EST 2004


On Sun, December 12, 2004 15:29, Markus Neteler said:
> (cc Silke)
>
> On Sat, Dec 11, 2004 at 05:53:29PM +0100, Moritz Lennert wrote:
>> Hello,
>>
>> In order to map some of the results of the GRASS Users Survey, I am looking
>> for a worldwide set of unique centroids per country. In the current data
>> sets
>> I have (all based on the ESRI world map) each country is represented by many
>> different polygons, each having its own centroid, but with the same country
>> name identifying it. Thus, when I try to use d.vect.chart I get as many
>> piecharts per country as there are polygons. I would obviously prefer to
>> have
>> only one chart par country.
>>
>> I know I can "clean" out the data sets I have, but if anyone has a
>> ready-to-go
>> free data set of unique centroids per country (or can direct me to a
>> possible
>> source), it would save me some work.
>
> Please have a look at the worldmap based on VMAP0 data from
> Silke Reimer/Intevation:
>
>  http://www.intevation.de/pipermail/freegis-list/2004-July/001784.html
>
>  ftp://ftp.gwdg.de/pub/misc/freegis/intevation/freegis/worlddata/
>
> Note that she used VMAP0 R3 (a bit old) for V0.1.
>
> There is a newer V0.2 also available, maybe based on a higher version
> but the tarball seems to be damaged.

Thanks, I'd already tried with v0.2 but it presents the exact problem I've
mentioned. See
http://moritz.homelinux.org/grass_survey/results/survey_responses.png
for a demonstration of what I mean: more than one area with the same country
name.

I remember actually creating a "one country - one centroid" data set a few
years ago, I hopefully should be able to find it at work on Monday...otherwise
I'll have to digitize the necessary centroids myself. Not the end of the world
either.

Moritz




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