contourf min max is it possible?

I have a large matrix Cp and using contourf(Cp) Is it possible to mark min and max values in the plot ?

Answer 1

[Chad Greene]

Here's an example you can run. If Cp is a matrix like this:

Cp = peaks(1000);

and you want to make a contourf plot, specify the values of the contour lines. Here I'm doing -3 to 2 at intervals of 0.75.

contourf(Cp,-3:0.75:2)

Answer 2

[Walter Roberson]

[minCp, minidx] = min(Cp(:));
[minrow, mincol] = sub2ind(size(Cp), minidx);
minleg = sprintf('Minima @ (%d,%d) = %.2f', mincol, minrow, minCp);

[maxCp, maxidx] = max(Cp(:));
[maxrow, maxcol] = sub2ind(size(Cp), maxidx);
maxleg = sprintf('Maxima @ (%d,%d) = %.2f', maxcol, maxrow, maxCp);

hold on
lh = plot( mincol, minrow, 'g+', maxcol, maxrow, 'r+', 'MarkerSize', 15);
legend(lh, {minleg, maxleg} );
hold off

[Casper Stroem]

Walter I am getting an error trying your solution

Answer 3

[Casper Stroem]

here is my contour plot 551x49 matrix, and i would like to show min and max value of Cp the exact position on the plot

Answer 4

[Casper Stroem]

Walter I am getting an error trying your solution

[Pronoy Das]

It should be:

[maxrow, maxcol] = ind2sub(size(Cp), maxidx);

and not

[maxrow, maxcol] = sub2ind(size(Cp), maxidx);