Dowe really need a configure time constant for struct _p_DMNetworkComponentHeader { PetscInt index; /* index for user input global edge and vertex */ PetscInt subnetid; /* Id for subnetwork */ PetscInt ndata; /* number of components */ PetscInt size[PETSC_DMNETWORK_MAXIMUM_COMPONENTS_PER_POINT]; PetscInt key[PETSC_DMNETWORK_MAXIMUM_COMPONENTS_PER_POINT]; PetscInt offset[PETSC_DMNETWORK_MAXIMUM_COMPONENTS_PER_POINT]; PetscInt nvar[PETSC_DMNETWORK_MAXIMUM_COMPONENTS_PER_POINT]; /* Number of variables */ PetscInt offsetvarrel[PETSC_DMNETWORK_MAXIMUM_COMPONENTS_PER_POINT]; /* offset from the first variable of the network point */ } PETSC_ATTRIBUTEALIGNED(PetscMax(sizeof(double),sizeof(PetscScalar))); Can't we just allocate this struct when needed and carry the size along? This design seem to go against the rest of what we do in PETSc? Thanks, Matt -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener https://www.cse.buffalo.edu/~knepley/ <http://www.cse.buffalo.edu/~knepley/>