MatCreateTile#

Explicitly build a matrix from four blocks.

Synopsis#

#include "slepcsys.h" 
PetscErrorCode MatCreateTile(PetscScalar a,Mat A,PetscScalar b,Mat B,PetscScalar c,Mat C,PetscScalar d,Mat D,Mat *G)

Collective

Input Parameters#

  • A - matrix for top-left block

  • a - scaling factor for block A

  • B - matrix for top-right block

  • b - scaling factor for block B

  • C - matrix for bottom-left block

  • c - scaling factor for block C

  • D - matrix for bottom-right block

  • d - scaling factor for block D

Output Parameter#

  • G - the resulting matrix

Notes#

The resulting matrix is built as

\[\begin{split}G = \begin{bmatrix} aA & bB\\ cC & dD \end{bmatrix}.\end{split}\]

In the case of a parallel matrix, a permuted version of G is returned. The permutation is a perfect shuffle such that the local parts of A, B, C, D remain in the local part of G for the same process.

Matrix G must be destroyed by the user.

The blocks can be of different type. They can be either MATCONSTANTDIAGONAL, or a standard type such as MATAIJ, or any other type provided that it supports the MatGetRow() operation. The type of the output matrix will be the same as the first block that is not MATCONSTANTDIAGONAL (checked in the A,B,C,D order).

See Also#

MatCreateNest()

Level#

developer

Location#

src/sys/mat/matutil.c

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