How to plot several sets (in different colours) with stem3-plotting function?

So I have several line array A which has columns [x, y, val1, val2]. For example, I want to have a single stem3-plot, where val1s are red and val2s are blue.

stem3(A(:, 1), A(:, 2), A(:, 3), 'red') % Will plot vals1 in red.

But how to get then vals2 in colour blue to the same stem3-plot?

Tried something similar which works with 2D-stem: http://www.mathworks.se/help/matlab/ref/stem.html ("Plot Multiple Data Series"), but it didn't work

stem3(A(:, 1), A(:, 2), [A(:, 3), A(:, 4)]); "Error using stem3. The length of X must match the number of columns of Z."

stem3(A(:, 1), A(:, 2), [A(:, 3); A(:, 4)]); "Error using stem3. X and Y must be same length as Z or the lengths of X and Y must match the size of Z."

Answer 1

[AJ von Alt]

You can use hold to overlay multiple plots on one set of axes. The following code demonstrates the concept using stem3 to plot the datasets.

% Random inputs
A = randn(20,3);
B = randn(20,3);

figure;
% Create a 3-D stem plot for dataset A
stem3( A(:,1) , A(:,2) , A(:,3) ,'blue')

hold on; % Activate hold

% Create a 3-D stem plot for dataset B
stem3( B(:,1) , B(:,2) , B(:,3) ,'red')

hold off %turn off hold

legend('A','B')

Answer 2

[Bruno Pop-Stefanov]

If you want to plot two series in the same axes in red and in blue, use hold on like in the following:

figure;
stem3(A(:, 1), A(:, 2), A(:, 3), 'r')
hold on
stem3(A(:, 1), A(:, 2), A(:, 4), 'b')
hold off

Answer 3

[Jouni Lohikoski]

Thanks you both. It ("hold") should be mentioned in the stem3 help page.