### Functions

Use set palette functions 4#4Rexpr5#5, 4#4Gexpr5#5, 4#4Bexpr5#5 to define three formulae for the R(gray), G(gray) and B(gray) mapping. The three formulae may depend on the variable gray which will take values in [0,1] and should also produce values in [0,1]. Please note that 4#4Rexpr5#5 might be a formula for the H-value if HSV color space has been chosen (same for all other formulae and color spaces).

Examples:

To produce a full color palette use:

         set palette model HSV functions gray, 1, 1

A nice black to gold palette:

         set palette model XYZ functions gray**0.35, gray**0.5, gray**0.8

A gamma-corrected black and white palette

         gamma = 2.2
         color(gray) = gray**(1./gamma)
         set palette model RGB functions color(gray), color(gray), color(gray)