Variable start positions for flow domain in SophT

[armantekinalp]

Currently Sopht only allows the flow domain to start at (0,0,0) . We should update such that user can start the domain at any point in space. We need to carefully see all the ImmersedBoundary interpolation kernels and update where ever we use flow domain grid positions.

[fankiat]

FWIW, you may find it helpful (hopefully) that some of this logic is implemented in sopht-mpi ImmersedBoundary interpolation kernels, since each of the subdomain technically has a different domain start. 😃

[armantekinalp]

That is a very good idea. @fankiat if there is any related file can you share the link here to get started.

[fankiat]

The related files that I can think of at the top of my head now should be in the numeric/immersed_boundary_ops. For example, the function here takes in an argument mpi_local_substart_coord_shift, which I guess would be the start position of your Eulerian mesh. The variable should be obtained upstream from the simulator when a user prescribes the Eulerian origin.