How to overlay pcolour figures?

Good afternoon,

   I am after a bit of advice again, if anyone has any time. 

   I've looked in the directory and at previous questions but can't seem to see a clear solution to my problem and I suspect that there is one. 

   I have five matrixes, (501,501,5). They show plume spread. I can plot each individually with pcolor no problem. 

   Is there a way to overlay the five into one figure? 

   Thanks for any help, advice, direction!

Answer 1

[Mike Garrity]

The pcolor function simply creates a surface object with color but no Z. You can set the FaceAlpha property on that to make it transparent.

[x,y] = meshgrid(linspace(-pi,pi,40));
h(1) = pcolor(cos(x).*cos(y));
hold on
h(2) = pcolor(sin(x).*sin(y));
hold off
h(2).FaceAlpha = .5;

[Chameleon17]

hmm, maybe I'm applying it to my code wrong, but it just turns everything black?

Answer 2

[Kelly Kearney]

Alternatively, assuming each dataset holds a zero wherever the plume is not, and the plume regions themselves don't overlap too much, you set the 0-values to NaN.

[x,y] = meshgrid(linspace(0,1,100));
a = exp(-((x-0.1).^2./0.1 + (y-0.1).^2)./0.1);
b = exp(-((x-0.9).^2./0.1 + (y-0.9).^2)./0.1);

a(a < 0.01) = NaN;
b(b < 0.01) = NaN;

pcolor(x,y,a);
hold on;
pcolor(x,y,b);
shading flat;

[Chameleon17]

Thank you for that.

I'm not sure if this bad or not, but in the end I've just added my five matrices together and plotted the result. It looks like what I was after. I'll need to think what's wrong with doing it this way though.

Thank you guys for your advice and help! Much appreciated!