[mapserver-users] accessing different band values in the same layer

[Helen San Segundo Navazo]

Hi,
I have a raster file with different bands inside it.
when I create my mapfile inside the layer tag I can define the bands I 
want to access with  PROCESSING "BANDS=4,2,1"
When I select 1 band I can access to its data using the EXPRESSION tag:
     CLASS
         NAME "0 - 5"
         EXPRESSION ([pixel] >= 0 AND [pixel] < 5)
         STYLE
         COLOR 80 0 0
         END
     END
But if I select more than one band, how can I do to acces to the 
different band values inside the same EXPRESSION tag? is it possible?

The problem is that I have wind information in different bands, in one 
band I have speed and in other band I have direction, and I have to draw 
the wind symbol depending on both values.
Is possible to acces to the different pixel band values inside the same 
EXPRESSION tag?
Thanks,
Helen