raster layers from point sources

[Charlton Purvis]

I’d go one of two ways – or perhaps both.

Create an sst LAYER w/ a bunch of CLASSes for each temp range.  E.g.

    CLASS
      EXPRESSION ([val] < -2.0)
      COLOR 0 0 159
    END
    CLASS
      EXPRESSION ([val] < -1.8)
      COLOR 0 0 191
    END
    CLASS
      EXPRESSION ([val] < -1.6)
      COLOR 0 0 223
    END

Or you could go the GMT (http://gmt.soest.hawaii.edu/) route.  I've done
that, too, w/ great results.  Basically, pass your data (in my case via an
ASCII dump to a GMT grid), make GMT draw the image, you georeference it by
slapping an appropriate .wld to this file, and then pass that image back to
MapServer to draw it.  You could do all of this ahead of time by creating
the images and storing them locally, or all of this could go on on-the-fly.
An advantage of going the GMT on-the-fly route is that you could choose to
draw contours or do any other type of GMT interpolation at the drop of a
hat.

Again, both have worked well for me.  The 1st option is nice and clean and
MapServer pure.  The 2nd option does have a few more moving parts, but it
produces a nice product, too.

I hope that helps.

Charlton

________________________________________
From: UMN MapServer Users List [mailto:MAPSERVER-USERS at LISTS.UMN.EDU] On
Behalf Of Christopher Condit
Sent: Friday, December 16, 2005 6:54 PM
To: MAPSERVER-USERS at LISTS.UMN.EDU
Subject: [UMN_MAPSERVER-USERS] raster layers from point sources

I’ve got some physical variables (such as sea surface temperature) at 1
degree intervals in an Oracle database (or perhaps in another vector
source).  What would be the best way to create a raster representation of
these values using MapServer/GDAL?  Any help would be appreciated