How to show only elliptic region in color?

Dear experts,

How can I get a plot like below in which no color will be shown outside of the ellipse?

If I use pcolor and I get a surface like below where outside of larger ellipse is filled with blue color that I don’t want.

A part of my code is given here.

pcolor(x1, y1, SS);

colormap jet

colorbar

hold on

quiver(x, y, sx, sy,'k'); % plot vector

hold on

x2 = x(TT > 0);

y2 = y(TT > 0);

ff2 = boundary(x2, y2);

plot(x2(ff2), y2(ff2),'r'); % plot outer boundary line

hold on

x3 = x(TT>0 & SS == 0);

y3 = y(TT>0 & SS == 0);

ff3 = boundary(x3, y3);

hold on

plot(x3(ff3), y3(ff3), 'r') % plot inner boundary line

Thanks in advanced.

Answer 1

[darova]

try this

[X,Y] = meshgrid( -10:0.2:10 );
Z = X.^2 + Y.^2;
ind = X.^2/5^2 + Y.^2/3^2 < 1;
Z(~ind) = nan;
pcolor(X,Y,Z)

[Abdul Mannan]

Thanks darova, technique works partially. Figure looks like below. And, How can I make the outside grid white or remove them form the plot?

[Image Analyst]

Don't use pcolor. pcolor doesn't show the last row or column anyway. Use imshow().

[darova]

Here

ind1 = X.^2/5^2 + Y.^2/3^2 > 1;         % remove outside part
ind2 = X.^2/3^2 + Y.^2/1^2 < 1;         % remove inside part
Z(ind1|ind2) = nan;
surf(X,Y,Z)
view(2)

[Abdul Mannan]

Thanks darova. I need to use pcolor because I will plot vector over the color plot. If I use pcolor, still grids are remained.

[darova]

Ok. What about my answer? Is it cool?

[Abdul Mannan]

Yes, your technique works. Thanks.

[darova]

You can accept my answer so i could be happier