using Mapserver for on-the-fly raster data?

[Jeff de La Beaujardiere]

Frank Warmerdam wrote:
> As of 4.6 (actually it might have been in 4.4 too), MapServer supports
> the ability to apply classification to non-8bit raster data.

OK, I have this mostly working in test mode with just a few colors. 
However, there remains a problem that I have not yet solved and may be 
an SRS/EPSG/WMS issue.  The raw binary input file has data from 0 to 360 
longitude, rather than -180 to 180. If my GetMap request has 
BBOX=-180,-90,180,90 I only get data in the East half of the image while 
the West half is blank. Some component apparently does not understand 
that longitude wraps around. I can get a complete image if 
BBOX=0,-90,360,90, but I do need to be able to use negative values for 
longitude.

Am I missing something, or is there a workaround for this problem?
Relevant snippets of my mapfile and VRT file are appended.

-Jeff DLB

--------------

   LAYER
     NAME "vrt"
     TYPE RASTER
     STATUS on
     PROJECTION
       "init=epsg:4326"
     END
     DATA "/home/delabeau/wms/test/precp.vrt"
     PROCESSING "SCALE=0,2"
     PROCESSING "SCALE_BUCKETS=4"
     CLASSITEM "[pixel]"
     CLASS
       EXPRESSION ([pixel] < 0.5)
       COLOR 206 29 0
     END
     CLASS
       EXPRESSION ([pixel] >= 0.5 AND [pixel] < 1.0)
       COLOR 225 115 0
     END
     CLASS
       EXPRESSION ([pixel] >= 1.0 AND [pixel] < 1.5)
       COLOR 237 170 0
     END
     CLASS
       EXPRESSION ([pixel] >= 1.5)
       COLOR 255 255 0
     END
     METADATA
       "wms_title" "Test VRT with GEOS4"
       "wms_layer_group" "/TestLayers"
       "wms_extent" "0 -90 360 90"
     END
   END

--------------

<VRTDataset rasterXSize="1000" rasterYSize="721">
   <SRS>EPSG:4326</SRS>
   <GeoTransform>0, 0.36, 0, 90, 0, -0.25</GeoTransform>
   <VRTRasterBand dataType="Float32" band="1" subClass="VRTRawRasterBand">
     <SourceFilename>/path/file</SourceFilename>
     <ImageOffset>602756000</ImageOffset>
     <PixelOffset>4</PixelOffset>
     <LineOffset>4000</LineOffset>
     <ByteOrder>MSB</ByteOrder>
     <ColorInterp>Palette</ColorInterp>
   </VRTRasterBand>
</VRTDataset>