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Hyperreduction: usage of SampleMeshManager #187
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Hi @JacobLotz, Thanks for your questions. ROM has some subtle complications that perhaps we should document better, and the sample mesh is a particularly tricky topic. A further complication is that results are very problem-dependent. Diffusion types of problems are typically the easiest for ROM, so the performance should be better for Now, to answer your questions: In general, here is a basic summary of the hyperreduction process.
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Hi @dylan-copeland, Thank you for your clarifications and your elaborate answers! The importance of I am currently working on a case of a one variable non-linear equation with a NURBS discretisation, but in a later stage I plan to apply the same to the Navier-Stokes equations. The choice of the used basis will probably important, just as in |
I am trying to implement a time independent non-linear reduced order model. The examples
nonlinear_elacticity_global_rom.cpp
andmixed_non-linear_diffusion.cpp
provide good examples of the usage of the used classes. However, I cannot fully understand the usage of the classSampleMeshManager
.This class seems to register the sampled variables, which are especially important for the hyper reduced non-linear term. I do not understand what
GetSampleFESpace()
produces. As the name indicates this seems to be some kind of sampled finite element space and the number of true variables seems to be somewhere in between the number of FOM and ROM variables.Quoting SampleMesh.hpp:
"The spaces defined on the sample mesh are referred to as sample mesh spaces, and they generally contain the sampled DOFs along with other unsampled DOFs."
An explanation for the number of variables being somewhere between the number of the FOM and the ROM variables would be the unsampled DOFs in the description above.
I have two questions:
nonlinear_elacticity_global_rom.cpp
it produces a large non-linear vector first, which it samples again afterwards to a much smaller vector. In this way it seems to be very FOM size-ish dependent. This is in the lines:The text was updated successfully, but these errors were encountered: