I solve diffusion equation in my program: \frac{\rho f}{dt} \, + \, \nabla \cdot (\rho f v) \, = \, \nabla \cdot (\rho D \nabla f) I create my geometry in gmsh: [Y-tube] I must definition subdomain and initialize F=0 and F=1. I imported my geometry, use this code: import meshio msh = meshio.re…

SImply use: dim = mesh.topology().dim() mvc = MeshValueCollection("size_t", mesh, dim) with XDMFFile("mesh.xdmf") as infile: infile.read(mvc, "name_to_read") surface_domains = cpp.mesh.MeshFunctionSizet(mesh, mvc) File("surface.pvd") << surface_domains

Thanks, and how can initialize f field thereafter?

Thanks, In your instance, you used: V = dolfin.FunctionSpace(mesh, "DG", 0) But in my problem f: F = FunctionSpace(mesh, 'P', 1) I try use “DG” elements, but my subdomain did’t interact each other And I still don’t understand how I can extract from surface_domains the subdomain

what do you imply when you say interact? the function you have sketched is 1 in one domain, 0 in the other. It is discontinuous across cell (i.e one data value per cell). For such data DG 0 is suitable.

Initialize in subdomain from gmsh

Uncategorized

dokken May 23, 2021, 10:05pm 4

See for instance: How to define different materials / importet 3D geometry (gmsh) - #2 by dokken

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Initialize in subdomain from gmsh

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