Same aspect ratio for the z-axis in a surface plot

I have a surface plot

and the x-axis and y-axis have the same ratio. I wish for the z-axis to have the same ratio. I have used

daspect ([1 1 1])

but it turns into a 2D plot.

I have used this code for the same aspect ratio for the x-axis and y-axis.

h=get(gca,'DataAspectRatio'); 
if h(3)==1
    set(gca,'DataAspectRatio',[1 1 1/max(h(1:2))])
else
    set(gca,'DataAspectRatio',[1 1 h(3)])
end

[Alexandra Roxana]

No, it doesn't work. I'm using this method for the 3D plot: https://scicomp.stackexchange.com/questions/26739/plot-2d-piecewise-constant-in-matlab-in-a-finite-elements-mesh

[Mathieu NOE]

maybe you get a 2D plot because the range of your z axis is 1000 times smaller than the range of x, y axes

[Alexandra Roxana]

@Mathieu NOE It still should be a solution for this.

Answer 1

[Simon Chan]

As mentioned by Mathieu NOE in the comment section, your z-axis data is 1000 times smaller than the range of x and y-axes data. Hence the ratio between them should be rescale accordingly.

Check whether this is what you want or not.

[X,Y] = meshgrid(1:0.5:10,1:20);
Z = sin(X) + cos(Y);
surface(X/5+1,Y/3.5,Z*1e-3)         % Just make sure the range of the demo data is close to your data
view(3)
daspect ([1 1 1e-3]);               

[Alexandra Roxana]

That seems to work. It would help me if the values would be multiplied by 10^-3; is there a way to do that?

[Simon Chan]

Similar approach with exponent of z-axis properly selected.

[X,Y] = meshgrid(1:0.5:10,1:20);
Z = sin(X) + cos(Y);
surface(X/2.5,Y/1.8,Z*1e-2)         % Just make sure the range of the demo data is close to your data
view(3)
ax=gca;
ax.ZAxis.Exponent = -2;         % Set the expoent to -2 here
daspect ([1 1 1e-2]); 

[Alexandra Roxana]

I'm afraid it isn't right: let's say a measure unit from the x-axis or y-axis is 1cm, on the z-axis is 0.01 cm so it isn't right. They have to be equal, for my surface plot it needs to be that way so some points won't be that isolated.

[Simon Chan]

According to your requirement, you should use:

%daspect ([1 1 1])

But I think it is not an optimal way to present the data, see the example below and the last plot is what you need.

tiledlayout(2,2,'TileSpacing','none');
[X,Y,Z] = peaks(20);
nexttile
surf(X,Y,Z*1e-3)
daspect ([1 1 1e-3]); 
nexttile
surf(X,Y,Z*1e-3)
daspect ([1 1 1e-2]); 
nexttile
surf(X,Y,Z*1e-3)
daspect ([1 1 1e-1]);
nexttile
surf(X,Y,Z*1e-3)
daspect ([1 1 1e-0]);

[Alexandra Roxana]

I see what you mean and indeed, daspect messes up also the x and y-axis. Maybe if I use a smaller step for each axis might it work?

[Simon Chan]

Imaging you put two 1 m rulers on the floor as the x and y-axis and your data on z-axis have a thickness like a sheet of paper, then you ask the program to display the entire data on a volume of 1 cubic meter. Then you can only find something near the floor and that's why you got a "2D" plot. So function daspect does a correct job without messes up anything on x,y and z-axis.

I do not have an answer for your question and I would recommend you to think how you would like to present your data.

[Alexandra Roxana]

That makes perfect sense! Thank you for all your explanations!

[Alexandra Roxana]

I guess I have to work with the time step; I think if the time step was very small on the x or y-axis, the z-axis would be well defined.

[Simon Chan]

Glad to see you come up with a new idea. Just curious your data along z-axis is also in time unit?

[Alexandra Roxana]

No, it is the solution so it doesn't work. I'm thinking at how I could plot this if for instance, I would measure on a piece of paper with a ruler, this is how I would like for it to look. The grid should be very detailed. This is how a part of the solution looks like: