Plotting two surface plots in the same figure using two different c... (2024)

Hi @Ira,

First, I will generate data for the two surface plots, I will use functions like peaks , if you want yiu can define your own data matrices.

[X, Y, Z1] = peaks(30); % Data for the first surface plot

Z2 = peaks(30) - 5; % Data for the second surface plot

Then I will plot the first surface plot using the 'turbo' colormap per your description.

figure;

surf(X, Y, Z1, 'FaceColor', 'interp', 'EdgeColor', 'none');

colormap turbo;

colorbar;

Then, plot the second surface plot using the 'gray' colormap and make it semitransparent by adjusting the alpha value, again per your description.

hold on;

surf(X, Y, Z2, 'FaceColor', 'interp', 'EdgeColor', 'none', 'FaceAlpha', 0.5);

colormap gray;

Finally, you can further customize the plot by adding labels, titles, adjusting the view, or any other modifications as needed.

xlabel('X-axis');

ylabel('Y-axis');

zlabel('Z-axis');

title('Combined Surface Plots');

view(3); % Adjust the view angle if needed

Please see attached plot. Hope, this answers your question.

Hi @Ira,

The updated code snippet demonstrates adjusting the colormaps and overlaying the axes,and efficiently presents two distinct surfaces with varying color representations. Here is updated code along with attached plot.

% Define the colormap for the second axis

colormap(gray);

% Generate meshgrid data

[X, Y] = meshgrid(-2:0.1:2);

% Sample data for surface plot 1

Z1 = X.^2 - Y.^2;

% Sample data for surface plot 2

Z2 = sin(X) + cos(Y);

% Create a figure

figure;

% Create subplots for each surface plot

ax1 = subplot(1,2,1); % Axes for surface plot 1

ax2 = subplot(1,2,2); % Axes for surface plot 2

% Plot the first surface on the first axis

surf(ax1, X, Y, Z1, 'FaceColor', 'interp', 'EdgeColor', 'none');

colormap(ax1, turbo);

% Plot the second surface on the second axis

surf(ax2, X, Y, Z2, 'FaceColor', 'interp', 'EdgeColor', 'none', 'FaceAlpha', 0.5);

% Adjust the colormap for the second axis

colormap(ax2, gray);

% Overlay the second axis on top of the first axis

set(ax2, 'Position', get(ax1, 'Position'));

% Hide the second axis

axis(ax2, 'off');

Replacing Z1 & Z2 data with the following data below will display the attached plot below.

Z1 = peaks(41)-5; % Data for the first surface plot with correct dimensions

Z2 = peaks(41)-5; % Data for the second surface plot with correct dimensions

You have two choices:

1. Use seperate plotting axes. Each axes can have its own colormap. Make sure you pass the axes handle into the colormap() calls. You can ax2 = axes('Position', get(ax1, 'Position')) to place the second axes exactly where the first axes is, and then be careful to pass ax1 or ax2 as appropriate to each graphics operation.
2. Alternately, plot normally with one colormap, and then call https://www.mathworks.com/matlabcentral/fileexchange/7943-freezecolors-unfreezecolors to convert the graphics object from indexed to RGB. Once the object is converted to RGB, colormap stops affecting it, so you can then go ahead and colormap the second palette.

Sean Cupitt on 2 Aug 2024 at 19:47

Walter Roberson on 2 Aug 2024 at 20:28

Assign two surface objects two different colormaps using Truecolor arrays

The recommended approach is to create an overlayed axes so that each surface gets its own axes and a colormap can be applied to each axes (doc link).

But let's explore a different solution. Instead of mapping colors, set the surface's color data using a Truecolor array. I've included a little helper function colormapToTruecolor to convert color map values into Truecolor values.

Why this is better than using axes overlays

Sometimes this problem is solved by overlaying two axes, assinging a surface and colormap to each axes, and making the top axes invisible. A lot of care must be taken to get this right. Several properties must match between the two sets of axes, the most important being axis position, axis limits, and axis direction, and DataAspectRatio, but other property mismatches between the two sets of axes can thrown off the correspondance. Then there's axes interactions. If you pan or zoom, the axes should move together. linkaxes along with linkprop can help with that but neither respond to pressing the restore button on the axes toolbar.

The approach above using Truecolor arrays requires a second invisible axes but its only purpose is to host the second colormap so the figure can have two colorbars. Importantly, the two objects are in the same axes so no wizardry is needed to share the same data space.

Also, the single-axes Truecolor approach allows for surfaces to intersect! The two figure below contain the same surfaces and the same viewing angles but the one on the left uses axes overlays which prevents the surfaces from intersecting!

Adam Danz on 2 Aug 2024 at 22:19