PLTvalueColor TCL UTILITIES USER MANUAL PLTvalueColor
SYNOPSIS
Convert value to color table index
PACKAGE
TCLPLT
NAME
PLTvalueColor
USAGE
set rV  [PLTvalueColor  V cMap]
INPUT DEFINITIONS
V - Value to convert to a color table index.
cMap - Array of color mapping coefficients. These can come from either a call to ColorBar or to PLTcolorMap.
RETURN DEFINITION
Returns the index into the color table associated with V.
DESCRIPTION
PLTvalueColor converts a value V to a color table index from the color mapping information contained in the array cMap. cMap is obtained from either a call to ColorBar or to PLTcolorMap. Values which produce color indices greater than the maximum color are set to the maximum and values which produce color indices less than 0 are set to 0.
ERRORS
None Generated
C BACKING
No
EXAMPLE(S)
EXAMPLE 1:Map values to color index. 
# START graphics

GraphicsOn TK RainBow 

# OBTAIN both a LOG and LINEAR color mapping for the range 1 to 10000.

PLTcolorMap 1.0 10000. LOG NO cA
PLTcolorMap 1.0 10000. LINEAR NO cB

# MAP as set of values using both the linear and log mapping and print
#   the resutls

for { set I 0 } { $I <= 10 } { incr I } {
   set V [expr $I * 1000.0 + 5.0] 
   set Ca [PLTvalueColor $V cA]
   set Cb [PLTvalueColor $V cB]
   puts stderr [format "Value %8.2f: COLOR (LOG) %3d - (LINEAR) %3d" $V $Ca $Cb]
}

> Value     5.00: COLOR (LOG)  44 - (LINEAR)   0
> Value  1005.00: COLOR (LOG) 190 - (LINEAR)  25
> Value  2005.00: COLOR (LOG) 209 - (LINEAR)  50
> Value  3005.00: COLOR (LOG) 220 - (LINEAR)  76
> Value  4005.00: COLOR (LOG) 228 - (LINEAR) 101
> Value  5005.00: COLOR (LOG) 234 - (LINEAR) 127
> Value  6005.00: COLOR (LOG) 239 - (LINEAR) 152
> Value  7005.00: COLOR (LOG) 244 - (LINEAR) 177
> Value  8005.00: COLOR (LOG) 247 - (LINEAR) 203
> Value  9005.00: COLOR (LOG) 251 - (LINEAR) 228
> Value 10005.00: COLOR (LOG) 254 - (LINEAR) 254
Apr 13, 2007