Lots of colours under XDRIVER

Michael Shapiro shapiro at zorro.cecer.army.mil
Mon Jan 6 12:42:27 EST 1992

In response to:

|I too use GRASS on a Sun (SunOS4.1.1,OpenWindows) but have found the fixed/
|floating cut off point to be at 220. More importantly, if I try to rescale
|an image using r.mapcalc to anything with more than 220 categories, I get
|an error when I try to display the image.
|eg. suppose I have a raster map with range 0-444, and I type the following
|GRASS 4.0 > d.colormode float
|GRASS 4.0 > r.mapcalc
|mapcalc> newmap = oldmap/2
|				[range 0-222]
|GRASS4.0 > d.rast newmap
|GRASS will then display this as a floating colour image with the exception of
|any cell values of 221 or 222, and give the message:
|reset_color: can't set color 256
|reset_color: can't set color 257
|This error is repeated for the number of categories over 220.
|Has anyone else experienced a similar problem, or know how to solve it ?

This is a known BUG in the current version of the XDRIVER both under X
windows from MIT and openwindows from SUN. Maps with 220-240 colors
will have this problem under colormode "float".

A fix is underway. When it is ready (maybe tomorrow) I will make it
available via anonymous ftp to moon.cecer.army.mil.

Michael Shapiro
U.S. Army CERL                  email:   shapiro at zorro.cecer.army.mil
Environmental Division          phone:   (217) 352-6511  ext 526
P.O. Box 9005                   fax:     (217) 373-7222
Champaign, Ill. 61826-9005

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