Frank,
Thanks for that advice, a further complication is that I'd like to be
able to specify the suitability values as part of the request.
Is there a way to apply some conditional processing based upon the
value of request parameters?
Andrew
On 1 Jul 2008, at 13:45, Frank Warmerdam wrote:
Andrew Mason wrote:
Hello List,
I wonder if anyone can anyone suggest a possible mechanism for
achieving the following?
I have two rasters covering the same area.
Raster A contains the suitability of the location for the growth
of Species A (on a scale of 1 to 30)
Raster B contains the suitability of the location for the growth
of Species B (on a scale of 1 to 30)
I would like to generate a layer that shows the result of the
following rule:
Display green at locations where Species A suitability is > 18
Otherwise if Species B suitability > 14 display blue
Otherwise display red.
Andrew,
I haven't tried this, but I think you could handle this with two
layers
in your mapfile, one for each raster. The first layer should be
for RasterB.
It should have one class with an expression selecting suitability
values
greater than 14 and a color of blue. The next layer should be for
RasterA
and have one class for suitabilities greater than 18 and a color of
green.
It should also have a second class with no expression and a color
of red.
There are some docs on raster classification in:
http://mapserver.gis.umn.edu/docs/howto/raster_data
However, if RasterA and RasterB are not dynamic, you might consider
producing the merged result as a preprocessing step instead of making
MapServer do the computations for each map render. It would be more
efficient. Such raster modelling could be done in GRASS, for
instance.
Best regards,
--
---------------------------------------
+--------------------------------------
I set the clouds in motion - turn up | Frank Warmerdam,
[EMAIL PROTECTED]
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush | President OSGeo, http://
osgeo.org
_______________________________________________
mapserver-users mailing list
mapserver-users@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/mapserver-users
