negative values and colors in Ascii Grids

[Carola Jesch]

Hi,

I have an contineous ASCII GRID (floating values) that I would like to
display in MapServer. This grid shows bathymetry (ocean) and elevation
(land) data. There are a lot of negative values for the ocean, starting from
-1500 to 0 and only a small range for the land (0 to 20). When I am trying
to display the grid, the entire image is black. Does MapServer support
negative values? How can I display the grid with colors?
I have tried to convert the Ascii file to a binary grid, but I don't know
how to create a colormap (*.clr). ArcGIS doesn't seem to support this or
does anyone of you how to do that?

Any help is welcome.
Thanks, Carola
 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Carola Jesch
Wetland Biogeochemistry Institute
Department of Oceanography and Coastal Science
Louisiana State University
3191 Energy, Coast & Environment Bldg.
Baton Rouge, LA,70803
e-mail: cjesch at cct.lsu.edu