## Plot solution of pde toolbox on a line (or submanifold)

on 31 Oct 2012

### Bill Greene (view profile)

I'm using the pde toolbox to solve a certain elliptic equation in 2D.

Solution is fine, although I do need to plot it along a given line, i.e. to cut a planar slice from the 3D mesh representing the solution.

I can't figure out a way that smartly involves the toolbox functions.

Any help appreciated.

## Products

### Bill Greene (view profile)

on 2 Nov 2012

Hi,

Here is one way to create such a plot. Assume you have the point matrix created by the PDE Toolbox mesher, p, and a solution vector, u. The function below will create a plot of that solution along a line defined by the x and y locations of the two end points. My example is for a solution on a unit square and I want a plot along the line (0,.5) to (1,.5). I want to include 25 points in the plot. As you can see, the real work is being done by the TriScatteredInterp function from core MATLAB.

```plotAlongLine(p, u, [0,.5], [1,.5], 25);
```
```function plotAlongLine(p, u, xy1, xy2, numpts)
x = linspace(xy1(1),xy2(1),numpts);
y = linspace(xy1(2),xy2(2),numpts);
F = TriScatteredInterp(p(1,:)', p(2,:)', u);
uxy = F(x,y);
figure; plot(x, uxy);
end
```

Bill

Alessandro

### Alessandro (view profile)

on 5 Nov 2012

Perfectly working! thanks!

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