3.4 Color scheme

The color scheme is used for determining the color of surfaces, isolines, isosurfaces and so on. The color scheme is defined by the string, which may contain several characters that are color id (see section Line styles) or characters ‘#:|’. Symbol ‘#’ switches to mesh drawing or to a wire plot. Symbol ‘|’ disables color interpolation in color scheme, which can be useful, for example, for sharp colors during matrix plotting. Symbol ‘:’ terminate the color scheme parsing. Following it, the user may put styles for the text, rotation axis for curves/isocontours, and so on. Color scheme may contain up to 32 color values.

The final color is a linear interpolation of color array. The color array is constructed from the string ids (including “bright” colors, see Color styles). The argument is the amplitude normalized between Cmin – Cmax (see Axis settings). For example, string containing 4 characters ‘bcyr’ corresponds to a colorbar from blue (lowest value) through cyan (next value) through yellow (next value) to the red (highest value). String ‘kw’ corresponds to a colorbar from black (lowest value) to white (highest value). String ‘m’ corresponds to a simple magenta color.

There are several useful combinations. String ‘kw’ corresponds to the simplest gray color scheme where higher values are brighter. String ‘wk’ presents the inverse gray color scheme where higher value is darker. Strings ‘kRryw’, ‘kGgw’, ‘kBbcw’ present the well-known hot, summer and winter color schemes. Strings ‘BbwrR’ and ‘bBkRr’ allow to view bi-color figure on white or black background, where negative values are blue and positive values are red. String ‘BbcyrR’ gives a color scheme similar to the well-known jet color scheme.

When coloring by coordinate (used in map), the final color is determined by the position of the point in 3d space and is calculated from formula c=x*c[1] + y*c[2]. Here, c[1], c[2] are the first two elements of color array; x, y are normalized to axis range coordinates of the point.

This document was generated on April 13, 2012 using texi2html 5.0.