Subdomain meshes and local to global index mapping

Hi all,

I'm new to Julia and Gridap, and I think it suits my purpose well to implement a multiscale method for solving, say, elliptic PDEs. I have done such implementations in Matlab and Python before, but Julia seems like a better option to me. The idea of the multiscale methods I am interested in is that, given a coarse mesh of the domain (not necessarily resolving the coefficients), one computes problem-adapted basis functions (associated with the coarse mesh entities) by solving local (fine-scale) problems. These local problems are posed on a subdomain composed of elements in the coarse mesh, and the corresponding fine mesh can be obtained by refining the coarse mesh restricted to the subdomain. So I am wondering if it is possible with Gridap to easily create fine subdomain meshes for computing the problem-adapted basis functions and then map the local DoFs to the global DoFs (so a mapping from the fine local subdomain mesh to a fine global mesh).

I would appreciate any suggestions on how to conceptually do this and which utilities to use.

Thanks in advance!

No files, tests, or entry points are named. Start by locating Gridap's mesh, subdomain, refinement, and degree-of-freedom mapping utilities, then determine whether they support the requested local-to-global workflow. Done would require a clearly specified and validated approach, or a scoped implementation request with relevant tests.

Written by the indexing model from the issue text.