Plot two solutions of PDE from different space.

Hello,

I have a very specific problem which I cannot solve it. I solved a PDE(1D, for instance u1, with the pdepe solver. The geometry was from 0 to 1 with 41 mesh points. I make the same one from 1 to 2 with 100 mesh points. The solution was u2.

I want to plot the solutions as one with the difference that I have a discontinuity at x point. However, I do not want a graph such as the two branch functions. I want as one with a vertical line in the point of discontinuous. I attached an image from the example pdex5 which MatLab provides.

I will be grateful for some ideas.

Answer 1

[Alan Weiss]

I suppose that the first mesh points are in a vector x1, and the second set of mesh points is in a vector x2. I also assume that the discontinuity is at x = 1.

 plot(x1,u1,'r')
 hold on
 plot(x2,u2,'b')
 plot([1,1],[u1(41),u2(1)],'k')
 hold off
 xlabel('x')
 ylabel('u')

Of course, you don't have to have different colors for each part of the plot.

If I misunderstood what you were asking, please ask again.

Alan Weiss

MATLAB mathematical toolbox documentation