I'm trying to solve a coupled micromagnetic problem on two domains with fenicsx v0.9.0 that is installed with conda involving: Magnetization (a 3D vector field), Scalar magnetic potential, and Lagrange multiplier to enforce unit norm of the magnetization. These fields are defined in a mi…

I do not have pygmsh and hence cannot execute the code and comment with certainty. But I feel you might be missing a term like this in your weak form: zero = fem.Constant(msh, default_scalar_type(0)) F3 = ufl.dot(zero*phi, phi)*dx F = F0 + F1 + F2 + F3 Additionally - and without understanding your…

Thank you for your answer. Unfortunately, this didn't help. I don't think it is related to the Lagrange term because problem persists even when I use only "m" and "phi". I've created another MWE that includes two domains: in one, linear elasticity is coupled with magnetostatics, and in the other, …

I managed to run your script. I do not know if it is the main problem or just a symptom but something is certainly off with your matrices. Doing the following: print("Size of A matrix: {}".format(self.A.getSize())) print("Size of x vector: {}".format(self.b.getSize())) gives Size of A mat…

Missing diagonal entry when solving mixed-domain PDE

dolfinx

Caglar April 28, 2025, 2:04pm 5

Thank you very much for pointing this out and helping, following solved my problem, Trouble solving mixed-domain PDE with BlockedNewtonSolver - #5 by dokken

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Missing diagonal entry when solving mixed-domain PDE

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