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r.what.color(1grass) GRASS GIS User's Manual r.what.color(1grass)


r.what.color - Queries colors for a raster map layer.


raster, querying, color table


r.what.color --help
r.what.color [-i] input=string [value=float[,float,...]] [format=string] [--help] [--verbose] [--quiet] [--ui]


Read values from stdin

Print usage summary

Verbose module output

Quiet module output

Force launching GUI dialog


Name of existing raster map to query colors

Values to query colors for

Output format (printf-style)
Default: %d:%d:%d


r.what.color outputs the color associated with user-specified category values in a raster input map.

Values may be specified either using the values= option, or by specifying the -i flag and passing the values on stdin, one per line.

For each value which is specified, a line of output will be generated consisting of the category value followed by the color, e.g.:

r.what.color input=elevation.dem value=1500
1500: 223:127:31

If the input map is an integer (CELL) map, the category will be written as an integer (no decimal point), otherwise it will be written in floating point format (printf("%.15g") format).

If the lookup fails for a value, the color will be output as an asterisk, e.g.:

r.what.color input=elevation.dem value=9999
9999: *

If a value cannot be parsed, both the value and the color will be output as an asterisk, e.g.:

r.what.color input=elevation.dem value=bogus
*: *

The format can be changed using the format= option. The value should be a printf()-style format string containing three conversion specifiers for the red, green and blue values respectively, e.g.:

r.what.color input=elevation.dem value=1500 format=’%02x:%02x:%02x’
1500: df:7f:1f

If your system supports the %m$ syntax, you can change the ordering of the components, e.g.:

r.what.color input=elevation.dem value=1500 format=’%3$02x:%2$02x:%1$02x’
1500: 1f:7f:df

Common formats:

  • Tcl/Tk: format="#%02x%02x%02x"
  • WxPython: format=’"#%02x%02x%02x"’ or format=’"(%d,%d,%d)"’




Glynn Clements


Available at: r.what.color source code (history)

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GRASS 7.8.5