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From: Jax Cao on 4 Aug 2010 14:48
Hi,

Several weeks ago, I posted a message of worldmap issue: http://www.mathworks.com/matlabcentral/newsreader/view_thread/287296
I hope Matlab professionals look at the post to see whether it is possible to modify their original codes. Now I have another issue related with worldmap color presentation and look for a possible answer.

I am not able to conserve colors using contourfm, contourm in the worldmap. I use 2007b but I guess the problem exists in other versions. Basically, color bands are distorted without freezeColors or removed after using freezeColors, a tool by John Iversen. Let me use the following example to illustrate, and I put the corresponding figures in the link:
http://www.jaxforum.net/apps/photos/album?albumid=9673658
so you can compare your figures with mine:

sz = get(0, 'screensize');
h = figure('position', [150 150 sz(3)*3/5 sz(3)*3/10]);
axes1 = axes('parent', h, 'position', [0.04 0.06 .45 .88]);
axes2 = axes('parent', h, 'position', [0.53 0.06 .45 .88]);
y = rand(40, 1)*40 ;
x = rand(40, 1)*80 ;
z = sqrt((x-40).^2 + (y-20).^2);
xlin = linspace(min(x),max(x),32);
ylin = linspace(min(y),max(y),32);
[X,Y] = meshgrid(xlin,ylin);
Z = griddata(x, y, z, X, Y, 'cubic');
axes(axes1)
h = worldmap([1 40], [1 80]);
contourfm(ylin, xlin, Z, [25, 35 42]);
colormap('Cool')
axes(axes2)
h = worldmap([1 40], [1 80]);
contourfm(ylin, xlin, Z, [25, 35 42]);
contourm(ylin, xlin, Z, 'k')

Now the color changed, and if I use freezeColors before the contourm, the result is good without any distortion.
i.e. replace contourm(ylin, xlin, Z, 'k') with the following two:
freezeColors
contourm(ylin, xlin, Z, 'k')

However there are still some issues with freezeColors. For example, freezeColors will remove color bands if I set the white color as the worldmap background. Please see:

figure
h = worldmap([1 40], [1 80]);
setm(h, 'FFaceColor', [1 1 1]);
contourfm(ylin, xlin, Z, [25, 35 42]); % here use the data above
colormap('Cool')
freezeColors

Now you will see that freezeColors remove the left cyan band.

What's the problem?

Thanks,

Jax Cao
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