You would use PETSC_NULL_DMLABEL but Matt needs to customize the PETSc Fortran stub for DMAddField() for you to handle accepting the NULL from PETSc.
Barry > On Dec 8, 2022, at 1:05 PM, Nicholas Arnold-Medabalimi <narno...@umich.edu> > wrote: > > Hi Petsc Users > > I am trying to use DMAddField in a Fortran code. I had some questions on > casting/passing NULL. I follow how to pass NULL for standard types (INT, > CHAR, etc). > > Is there a method/best practice for passing NULL for Petsc type arguments? > (In this case DMAddLabel I'd want to pass NULL to a DMLabel Parameter not an > intrinsic type) > > For the 2nd question, In some cases in C we would cast a more specific object > to Petsc Object > DMAddField(dm, NULL, (PetscObject)fvm); (where fvm is a PetscFVM type) > Is there a method or practice to do the same in Fortran. > > Thanks > Nicholas > > -- > Nicholas Arnold-Medabalimi > > Ph.D. Candidate > Computational Aeroscience Lab > University of Michigan
