SNESDefaultMatrixFreeMatAddNullSpace

Provides a null space that an operator is supposed to have. Since roundoff will create a small component in the null space, if you know the null space you may have it automatically removed.

Synopsis

int SNESDefaultMatrixFreeMatAddNullSpace(Mat J,int has_cnst,int n,Vec *vecs)
Collective on Mat

Input Parameters

J - the matrix-free matrix context
has_cnst - PETSC_TRUE or PETSC_FALSE, indicating if null space has constants
n - number of vectors (excluding constant vector) in null space
vecs - the vectors that span the null space (excluding the constant vector); these vectors must be orthonormal

Keywords

SNES, matrix-free, null space

Location: src/snes/interface/snesmfj.c
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