[Mapserver-users] Re: Display polygon layer as circle layer

[pkishor_98]

--- In mapserver-users at yahoogroups.com, Stefan Schwarzer
<stefan.schwarzer at g...> wrote:
..
> Now I thought perhaps it would be more meaningful if I 
> would overlay the 
> geospatial/background image with a "circle-layer", 
> instead of a 
> "polygon-layer". The size or the color of the circles 
> would represent then 
> the value of the country. This would leave enough space 
> to see the 
> background image, but one could still recognize the 
> different categories of 
> the statistical layer.
> 
> Is there a simple way to accomplish this? Do I have to 
> create from the 
> polygon shapefile a point shapefile on-the-fly, before 
> then displaying the 
> latter?

1. create a subroutine that takes an x,y pair, and a radius, and
creates a circle shape. 

2. create a new layer.

3. loop through all the polygons in the poly layer and call the
subroutine for every shape feeding it the current poly's centroid, and
a radius value "prorated" for the attribute value you want to map.

Puneet.