Defining surfaces not only in terms of z
I have three different surfaces and I want to display them all in one drawing.
The problem is that I have one surface defined in terms of z (which means I got the x and y values and a grid that gives the z values for each combination) and two others that are defined in terms of x. This means that there are different z-values for the same x, y-pair.
My idea:
figure
surf(x,y,zgrid)
hold on
surf(x,ygrid,z)
surf(x,ygrid2,z)
hold off
I was hoping MATLAB would handle this on its own, but it doesn't. Do you have any ideas how to get the results you want? I want to show them all in one graph to show the cross sections.
Here's an image of how it should look more or less:
If there is a nicer way to show this, please let me know.
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You have not indicated what exactly is going wrong, but I would venture to assume that you got an error similar to the following when you tried to build your second surface:
Error using surf (line 82)
Z must be a matrix, not a scalar or vector.
I assume that your variables x
, y
and z
are vectors, not matrices. The function surf
allows you to enter inputs x
and y
, which are then expanded into matrices using meshgrid
. It doesn't do this for input z
.
Your best bet, in my opinion, is to just use matrices for all your inputs. Here's an example where I do it (using meshgrid
) to plot three surfaces of a cube:
% Top surface (in z plane):
[x, y] = meshgrid(1:10, 1:10);
surf(x, y, 10.*ones(10), 'FaceColor', 'r');
hold on;
% Front surface (in y plane):
[x, z] = meshgrid(1:10, 1:10);
surf(x, ones(10), z, 'FaceColor', 'b');
% Side surface (in x plane):
[y, z] = meshgrid(1:10, 1:10);
surf(ones(10), y, z, 'FaceColor', 'g');
axis equal
And here's the plot:
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