I have the following L-shaped block with equally spaced grid points that I want to solve Laplace’s Equation w/ a Dirichlet Boundary Condition over: [L_grid] Initially, I wrote up a Jacobi iteration solver to solve the Euler Backward discretized partial difference equation to see what the solution…

There are many meshing tools out there, such as gmsh, ftetwild, netgen that come with a Python interface. Your use-case seems quite special, and I haven’t seen this specific kind of mesh generated with either. Please note that since DOLFINx only requires the array data structures, you are free to …

This doesn’t really answer your question, but here’s a quick trick for creating an Lshape: import dolfinx from mpi4py import MPI import numpy as np bounds = [[0.0, 0.0], [1.0, 1.0]] # Original bounds of rectangle xcutoff, ycutoff = 0.4, 0.6 # Cutoff to make L-shape mesh = dolfinx.mesh.create_re…

I think that’s a good start to help show me some tricks and gain further insight into the moving parts under the hood when creating a mesh like midpoints, cells, etc. I’m still very new to all of this. How would you handle something much more unorthodox like the following below num_of_points = 11;…

See for instance: I need to create stuctured uniform, structuted non-uniform, and unstructured mesh in 2D - #5 by dokken which shows you how to define a uniform structured grid to get a similar structure to what you want.

Thank you! I have taken a look at what you have provided, and the code works on my end. I’m guessing my grid type is “structured non-uniform”, and my prior example was a portion of a “structured uniform” grid. The vertex_to_dof_map_vectorized and perturb_mesh certainly look more advanced than what I…

[image] fea: The vertex_to_dof_map_vectorized and perturb_mesh certainly look more advanced than what I’m capable of understanding at the moment, but thankfully it looks like the only thing I need to mess around with are the user-defined expressions to see if I can’t implement a way to randomly …

This looks more in line with what I was looking for. I touched up my code a little as I noticed some mistakes num_of_points = 4; N = num_of_points-1; dx,dy = 1/N,1/N j,l = np.arange(0,N+1),np.arange(0,N+1); x = j*dx;y = l*dy; [X,Y] = np.meshgrid(x,y) Y = np.zeros((N+1,N+1)); for n in range(1,N+1…

The nodes do not have to be in a specific order.

[unevenly_layered_mesh] Looks like it worked. Now I just need to find a way to the creation of cells done for me and that will be the final step for creating a mesh, and then I can move on to latter steps of solving a PDE on the mesh. There’s probably a function in dolfinx or a python package out …

I made a nested for loop to make grid cells out of the points as a band-aid solution for creating 2D rectangular meshes of varying sizes without manually inputting each point and creating each cell by hand. num_of_points = 11; N = num_of_points-1; dx,dy = 1/N,1/N j,l = np.arange(0,N+1),np.arange(0…

Of those you mentioned, I actually have tried GMSH and used its GUI to make a 2D grid, the issue was that when I exported the mesh file as a .mesh file, something weird would happen to the original mesh’s edges that I don’t know how to explain. I’ll try to give the others a try. And to your comment…

First time getting started with Fenics (and using a finite element analysis package in general), could I have some advice or help on a problem I'm working on?

mesh

dokken June 23, 2025, 2:46am 6

Another alternative is to generate the grid by hand, as sketched out in:

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First time getting started with Fenics (and using a finite element analysis package in general), could I have some advice or help on a problem I'm working on?

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