Hallo
I'm solving a PDE problem which needs the integration over different parts of the boundary and over interior facets to impose many different boundary conditions. The conditions imposed vary in the different geometries I want to deal with, so in some cases there are parts of the variational form integrated on an empty facet region. So there are terms integrated over ds(n), but no facet marked with n. There are two things I don't understand.
- When I add these terms integrated on empty facet region, the assembly time increases of a factor of about 100. This may just be due to the additional terms which make the form more complex and involve interior facet integrals.
- The assembled Jacobian becomes almost twice large in terms of memory required. Is my program filling it with zeros?
I expected to get the very same result with just a little time more to assemble matrices, since the additional terms are just on boundaries.
Am I doing something wrong or is this expected? Sorry if my question is too basic.
Thank you.
