Hi, I tried to split a vector created by ufl.nabla_grad into its components but I failed to get the correct shape. I’m providing a minimal work example that’s adapted from the tutorial : from mpi4py import MPI from dolfinx import mesh from dolfinx import fem import numpy as np import ufl from petsc4…

Hi Francesco, thanks for the reply and sorry for making these confusions. I have provided code adapted from the fenicsx tutorial (and I confirm it can be run on my computer) and edited my question. Can you please take a look again? Thanks a lot

Hi. When working with mixed formulations, like VectorFunctionSpace, you need to collapse the functions (see for example Meaning of .collapse() or here ): Taking grad_uh_x=grad_uh_x.collapse() grad_uh_y=grad_uh_y.collapse() print(uh.x.array.shape, grad_uh_value.x.array.shape, grad_uh_y.x.array.shap…

Failed to split a vector

dolfinx

francesco-ballarin May 12, 2024, 5:20am 2

Read Read before posting: How do I get my question answered?. The code you posted is not reproducible, hence it’s unlikely anyone will be able to help.

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Failed to split a vector

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