masked MLP ROMs

[gokhalen]

Is it possible to create masked MLP based ROMs by replacing the linearDecoder in runMaskedLSPG from the unsteady_masked_galerkin_vs_lspg_advdiff1d_pod example with a decoder obtained from an autoencoder network? fomInitialState and romState will have to be set corrrectly; and finally romState will have to be decoded correctly and returned. Please let me know if I'm thinking in the correct direction.

[fnrizzi]

for MLP, the hyperreduction is not as trivial as the linear basis. i dont think you can select subsets but i might be wrong. @jtencer might be able to say more about this since he has an intern working on this

[gokhalen]

@fnrizzi So, is it right to say that hyper-reduction in Pressio is limited to the linear subspace ROMs?

[fnrizzi]

@gokhalen yes, because there is no clear hyp-red for nonlinear things