# Example 8 -- Demonstrate various image palettes (Color)
#
# Contributed 10 Aug 1994 by Dan Kelley <Dan.Kelley@Dal.Ca>.

`Panel \label'
{
    set y margin .y.
    draw axes none
    set clip postscript on
    draw image
    set clip postscript off
    draw axes frame
    draw image palette                                                  \
        left {rpn .min. .inc. -}                                        \
        right {rpn .max.  .inc. +}                                      \
        increment .inc.                                                 \
        box                                                             \
        {rpn ..xmargin.. ..xsize.. + .space. +}                         \
        {rpn ..ymargin.. ..ysize.. 2 / + .ph. 2 / -}                    \
        {rpn ..xmargin.. ..xsize.. + .space. + .pw. +}                  \
        {rpn ..ymargin.. ..ysize.. 2 / + .ph. 2 / +}
    draw label "\.word1." at                                            \
        {rpn ..xmargin.. ..xsize.. + .space. + .pw. + "M" width +}      \
        {rpn ..ymargin.. ..ysize.. 2 / + "M" ascent 2 / -} cm
    .y. += {rpn ..ysize.. .space. +}
}
.w. = 5                         # image width
.h. = 2.5                       # image height
.pw. = 5                        # palette width
.ph. = 1                        # palette height
.space. = 0.5                   # space between things
set x margin 1
set x size .w.
set y size .h.
# Planar data
set x grid 0 1 /5
set y grid 0 1 /6
read grid data 6 5
1 2 3 4  5
2 3 4 5  6
3 4 5 6  7
4 5 6 7  8
5 6 7 8  9 
6 7 8 9 10
.min. = 1
.max. = 9
.inc. = 1
set image range .min. .max.
convert grid to image

.y. = 1                         # start at bottom
# Each panel is adjusted to lie above last

#
# (1) HSB schemes (like mixing light sources)

# Ugly and useless
set image colorscale hsb 0.0   1.0 1.0 .min. hsb 1.    1.0 1.0 .max.
Panel "1. Full spectrum (HSB blending)"

# Nicer, but a lot of green
set image colorscale hsb 0.0   1.0 1.0 .min. hsb 0.666 1.0 1.0 .max.
Panel "2a. Spectrum from red to blue (HSB blending)"

set image colorscale hsb 0.0   1.0 1.0 .min. hsb 0.666 1.0 1.0 .max.
image colorscale ^= 0.5
Panel "2b. As 2a but colorscale to 1/2 power"

set image colorscale hsb 0.0   1.0 1.0 .min. hsb 0.666 1.0 1.0 .max.
image colorscale ^= 0.25
Panel "2c. As 2a but colorscale to 1/4 power"

set image colorscale hsb 0.0   1.0 1.0 .min. hsb 0.666 0.80 0.5 .max.
Panel "2d. As 2a but with blue being dirty"

set image colorscale hsb 0.666 0.0 1.0 .min. hsb 0.666 1.0 1.0 .max.
Panel "3. White-blue (HSB blending)"

# (2) RGB schemes (like mixing paints)
.y. += .space.

set image colorscale rgb 1.0 0.0 0.0 .min. rgb 0.0 0.0 1.0 .max.
Panel "4a. Red-blue (RGB blending)"

set image colorscale rgb 1.0 0.0 0.0 .min. rgb 0.0 0.0 1.0 .max. increment 2
Panel "4b. As 4a but quantized"

quit