blue-white-red colormap to current figure

orey

POLARMAP applies a "polarized" blue-white-red colormap to current figure,
        and adjusts the color axis limits to be centered to zero.

        POLARMAP(M) fixes the number of colors to M (default is 64).

        POLARMAP(MAP) applies linear shading to white to the center of colormap
        MAP which can be any of existing colormaps (an Mx3 matrix of RGB).

        POLARMAP(MAP,C) uses exponent C to modify the shading contrast. Default
        is C = 1 for linear shading. Use C = 2 to strengthen the shading, or
        C = 0.5 to attenuate it.

        C=POLARMAP(...) returns an M-by-3 matrix containing the colormap, that
        can be used with COLORMAP function like other colormaps.

        Examples:
                pcolor(peaks), shading interp
                polarmap, colorbar

        then try the following
                polarmap(jet,0.5)