**petsc-main 2021-04-20**

# PETSCSPACESUM

"sum" - A PetscSpace object that encapsulates a sum of subspaces. That sum can either be direct or concatenate a concatenation.For example if A and B are spaces each with 2 components, the direct sum of A and B will also have 2 components while the concatenated sum will have 4 components.In both cases A and B must be defined over the same number of variables.

### See Also

PetscSpaceType, PetscSpaceCreate(), PetscSpaceSetType()

### Level

intermediate

### Location

src/dm/dt/space/impls/sum/spacesum.c

Index of all SPACE routines

Table of Contents for all manual pages

Index of all manual pages