When representing "polarized" data for which zero and sign are meaningful (like for instance, a gravity anomalies map), it is useful to have a colormap where white stands for zero value, and greater magnitudes are plotted as colors with increasing saturation.

This little function POLARMAP has two different usages:

• proposes a new red-white-blue colormap that is standard for this purpose (same usage as other Matlab colormaps);
• applies a zero-center white shading to any existing colormap, like JET or HSV, or user defined.

pcolor(peaks), shading interp
polarmap, colorbar

polarmap(jet,0.5)

François Beauducel, IPGP, beaudu, beauducel@ipgp.fr

Type 'doc polarmap' for help and syntax.