Surface plot problem with mesh

Hello, I've got a code that solves pde system. As a result I've got matrix with values in different points (coordinate and time layer). Now I'm trying to plot the surface like this

     figure
     [x1,y1]=meshgrid(time,x);
     surf(x1,y1,u(:,:),'EdgeColor','black');
     colormap(copper)
     set(gca,'linewidth',2)
     shading interp;
     grid on;
     hold on;

where x and time are vectors of coordinate and time points, u is the result matrix. But the surface looks very strange.

 How can I add the lines on this surface? Like this

Answer 1

[Mischa Kim]

Danila, remove

 shading interp;

[Mischa Kim]

Very interesting. Could you attach your data ( x,time,u ) as a .mat file? Also, for better readability, please add comments as comments, not answers.

[Danila Zharenkov]

Here is my .m file with code. x and time are the vectors of grid points for PDE solution.

[Mischa Kim]

It's the huge number of data points that make the surface mesh lines turn the entire plot black. You can see the effect when reducing m and tmax.

So what you should be able to do, is to plot on top of your original plot an extra surface mesh (using the hold command) with a reduced number of data points.

[Danila Zharenkov]

You are right, with reduced number of data points it works.

Do you mean that I should solve this system second time with reduced number of points and plot it on the first surface?

[Mischa Kim]

Or simply down-sample the matrices. Would this work:

 figure;
 [x1,y1] = meshgrid(time,x);
 xsam = 1:5:size(x1,1);     % the 5 sets the lines spacing
 ysam = 1:3000:size(x1,2);
 surf(x1(xsam,ysam),y1(xsam,ysam),u(xsam,ysam),'EdgeColor','black');
 colormap(copper);

You still got all the data (for analysis), for visualization the down-sampled plot should be sufficient.

[Danila Zharenkov]

Thanks! That works.

Answer 2

[Danila Zharenkov]

I was trying to remove shading. Here's the result

 It's funny, I can't understand what going on with this plot.

[Mischa Kim]

Please add comments as comments, not answers.

Answer 3

[Kelly Kearney]

The wireframe function will give the effect you're looking for:

[x,y,z] = peaks(500);
surf(x,y,z);
shading flat;
wireframe(x,y,z,20);