Suppose I have a mesh Th defined in the square from x = 0 to 1, y = 0 to 1. I solve a PDE on this mesh, getting solution u. Now I want to know the line integral of u along the straight path from (0, 1/2) to (1, 1/2), that is, along a horizontal line that goes through the center of the square. What i…

I think you should use levelset keyword for the integration. something like int1d(Th, levelset=phi)(...) see doc here

Hi. I looked at the documentation, but I didn’t really understand what “levelset” does. How would adding this flag allow me to integrate along a given path?

take this example . func r = sqrt(xx +yy); real lc = int1d(Th,levelset=r-1.)(1.) ; here it integrates along the circle of radius one. Basically the phi in int1d(Th, levelset=phi)(...) is the parametric equation along which you integrate.

Hi, I managed to get two domains: one big domain and inside that big domain, I have a small domain. I need to get line integral around the small domain as well as area integral. I am getting some value as one d line integral but the area integral is zero. Can you suggest what is the best way of doi…

see it: [image] How to 1d intergrate along x/y direction in 2d mesh General Discussion Now I have a mesh Th defined in the square from x = 0 to 1, y = 0 to 1. I solve a PDE on this mesh, getting solution u. Then I want to know the line integral of u along y to get ∫𝑢𝑑𝑦, …

Thanks, but in my case, I have the labels available. I have a problem in getting area integral for f(u)dxdy in the smaller domain (black mesh). Mesh Th is defined for the whole domain (green+black) and int2d(Th,1)(f(u)) doen’t give me any result. 1 is the labels of inner boundary (black).

I am not sure this is what you are looking for, but if you do a 1d integral, int1d(Th,BoundaryLabel), then BoundaryLabel is the label of your border. From what I see, you do a 2d integral, with a label. the 2d integrals work like this: int2d(Th,RegionLabel) and here RegionLabel is the label of the…

How to 1D integrate along a path inside mesh

General Discussion

Emma87 (Emmanuel Yarleque Medina) September 15, 2021, 12:52am 6

see it:

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How to 1D integrate along a path inside mesh

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