how can i plot a contour plot over a imagesc?

how can i plot a contour plot over a imagesc?

Answer 1

[Akira Agata]

The solution would be as follows:

I think you should adjust 'LineColor' to clearly visualize your contour plot over imagesc.

% Sample data
z = peaks;

% contour over imagesc
figure
imagesc(z);
hold on;
contour(z,'LineColor','w');

[Mel Lin]

hello Akira, when I plot the contour plot on top of the imagesc it changes my image plot to consist of only one color instead of the full range of colors that it had prior to added the contour plot. how do i fix this Thanks!

[Akira Agata]

Hi Mel-san, I think that is due to the range difference. When range of image plot data (for example, z1 in the following code) and contour data ( z2 ) is different, and try to display in one figure, then colorbar range will be set to cover both image and contour data.

So, please set colorbar range explicitly by using caxis function. The following is one example and I hope it will solve your problem ! :-)

% Sample data
z1 = peaks;
z2 = 50+z1;

% contour over imagesc
figure
imagesc(z1);
cRange = caxis; % save the current color range
hold on;
contour(z2,'LineColor','w');
caxis(cRange);  % set the color range to the previous one

Answer 2

[Mohamed Ahmed]

%check out this Code for imagesc overlaid by contour lines

figure;

z = peaks;

imagesc(z)

axis xy; % Imagesc starts at the bottom of figure need for a flip

h_ax = gca;

h_ax.Colormap = cool;

h_ax_c = axes('position', get(h_ax, 'position'), 'Color', 'none');

contour(h_ax_c, z, [-8:2:10], 'ShowText', 'on');

h_ax_c.Color = 'none';

h_ax_c.Colormap = autumn;

h_ax_c.XTick = [];

h_ax_c.YTick = [];

title('Colormap Cool')