proportionnal symbols

[Stephen Lime]

There is no current way to pull symbol size from an attribute column (although under the
new 3.4 architecture it will be easy to add). You have a couple of options. You can obviously
use CLASS objects to change symbol sizes as you would colors. You could vary both if you
wanted based on multiple items, that might result in a large number of classes which could
be tough to manage. Is there any reason CLASSes won't work? Looking at the example you
sent that would seem to be the ticket.

The other option is to develop maps using MapScript were you have total control. You could
easily modulate symbol size by an attribute value on a feature-by-feature basis. For moderate
sized datasets this wouldn't be that inefficient.

Steve

Stephen Lime
Internet Applications Analyst

Minnesota DNR
500 Lafayette Road
St. Paul, MN 55155
651-297-2937

>>> Riccardo Cohen <rcohen at dial.oleane.com> 01/08/01 04:54AM >>>
Hi,
I practice Map Server for a couple of days, and find it very performant to display maps.
Our need is to put statistical datas on the map. I began to use CLASS object to change the color.

When it is to display rates, it is ok. But when I want to display for example the number of olympic successes at Sydney 2000, the proportionnal symbols is the best, as we did it at http://www.makeyourmap.com/Sydney2000 .

Is it possible to display a symbol directly proportionnal to the data without using the class object (which will give the same size for many different values).

I could not find any information in the doc and no sample in the gallery.

Thanks

-- 
Riccardo Cohen

Articque
Les Roches
37230 Fondettes
France
email = rcohen at dial.oleane.com 
web = http://www.articque.com 
tel: +33 02 47 49 90 49
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