[GRASSLIST:2486] r.mapcalc question

[Kevin Slover]

hello everyone, just a quick question about r.mapcalc to understand what
is going on right now...
    I am using the example in the man pages for the command to set map
values below a certain point to null, and trying to create a mask
layer.  What I am using is:
depth2.5 = if(sheetcomb.dem<2.5,null(),2.5)

when trying to using depth2.5 as a mask, there are 255
categories...which is not true of course, since I am working with
elevation/depth data...where are these 255 categories coming from??
 Thanks...
also, is it possible to use the following command:
depth2.5 = if(0>sheetcomb.dem<2.5,null(),2.5) ??

I am trying to basically eliminate heights greater than 0 and less than
2.5...

thanks....

--
        LTJG Kevin Slover,NOAA   GIS Specialist/Meteorologist/Oceanographer
              Tropical Prediction Center/National Hurricane Center
                    11691 SW 17th Street Miami FL 33165
                 Work: (305) 229-4456 Fax : (305) 553-1264


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