MatDiagonalSet

Computes Y = Y + D, where D is a diagonal matrix that is represented as a vector. Or Y[i,i] = D[i] if InsertMode is INSERT_VALUES.

Synopsis

#include "petscmat.h"  
PetscErrorCode MatDiagonalSet(Mat Y, Vec D, InsertMode is)

Neighbor-wise Collective

Input Parameters

• Y - the input matrix

• D - the diagonal matrix, represented as a vector

• i - INSERT_VALUES or ADD_VALUES

Note

If the matrix Y is missing some diagonal entries this routine can be very slow. To make it fast one should initially fill the matrix so that all diagonal entries have a value (with a value of zero for those locations that would not have an entry).

See Also

Matrices, Mat, MatShift(), MatScale(), MatDiagonalScale()

Level

intermediate

Location

src/mat/utils/axpy.c

Examples

src/ksp/ksp/tutorials/ex21.c
src/tao/constrained/tutorials/tomographyADMM.c
src/tao/pde_constrained/tutorials/elliptic.c
src/tao/tutorials/ex4.c
src/tao/unconstrained/tutorials/burgers_spectral.c
src/ts/tutorials/ex50.c

Implementations

MatDiagonalSet_MPIAIJ in src/mat/impls/aij/mpi/mpiaij.c
MatDiagonalSet_SeqAIJ in src/mat/impls/aij/seq/aij.c
MatDiagonalSet_IS in src/mat/impls/is/matis.c
MatDiagonalSet_Nest in src/mat/impls/nest/matnest.c
MatDiagonalSet_MPISELL in src/mat/impls/sell/mpi/mpisell.c
MatDiagonalSet_Shell in src/mat/impls/shell/shell.c

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