Index: /issm/trunk-jpl/src/m/plot/colormaps/demmap.m
===================================================================
--- /issm/trunk-jpl/src/m/plot/colormaps/demmap.m	(revision 14257)
+++ /issm/trunk-jpl/src/m/plot/colormaps/demmap.m	(revision 14257)
@@ -0,0 +1,62 @@
+function cmap = demmap(ncolors,minZ,maxZ);
+%DEMMAP - concatenate sea and land color depending on zmin and zmax
+%
+%   Usage:
+%      cmap = demmap(n,zmin,zmax)
+
+if nargin<3,
+	help landseacolor
+	error('3 arguments necessary');
+end
+
+if minZ == maxZ;
+	maxZ = minZ+1;
+end
+
+% determine appropriate number of sea and land colors
+if minZ == maxZ;
+	maxZ = minZ+1;
+end
+
+cmn = minZ;
+cmx = maxZ;
+
+% determine appropriate number of sea and land colors
+if minZ >= 0
+	nsea = 0;
+	nland = ncolors;
+elseif maxZ <= 0
+	nland = 0;
+	nsea = ncolors;
+else
+	% find optimal ratio of land to sea colors
+	maxminratio = maxZ/abs(minZ);
+	n1 = floor(ncolors/2);
+	n2 = ceil(ncolors/2);
+	if maxminratio>1
+		sea = (1:n1)';
+		land = (ncolors-1:-1:n2)';
+	else
+		land = (1:n1)';
+		sea = (ncolors-1:-1:n2)';
+	end
+	ratio = land./sea;
+	errors = abs(ratio - maxminratio) / maxminratio;
+	indx = find(errors == min(min(errors)));
+	nsea = sea(indx);
+	nland = land(indx);
+
+	% determine color limits
+	seaint = abs(minZ)/nsea;
+	landint = maxZ/nland;
+	if seaint >= landint
+		interval = seaint;
+	else
+		interval = landint;
+	end
+	cmn = -nsea*interval*(1 + 1e-9);      % zero values treated as land
+	cmx = nland*interval;
+end
+
+clim = [cmn cmx];
+cmap = [seacolor(nsea);landcolor(nland)];