MatCreateConstantDiagonal#

Creates a matrix with a uniform value along the diagonal

Synopsis#

#include "petscmat.h" 
PetscErrorCode MatCreateConstantDiagonal(MPI_Comm comm, PetscInt m, PetscInt n, PetscInt M, PetscInt N, PetscScalar diag, Mat *J)

Collective

Input Parameters#

  • comm - MPI communicator

  • m - number of local rows (or PETSC_DECIDE to have calculated if M is given) This value should be the same as the local size used in creating the y vector for the matrix-vector product y = Ax.

  • n - This value should be the same as the local size used in creating the x vector for the matrix-vector product y = Ax. (or PETSC_DECIDE to have calculated if N is given) For square matrices n is almost always m.

  • M - number of global rows (or PETSC_DETERMINE to have calculated if m is given)

  • N - number of global columns (or PETSC_DETERMINE to have calculated if n is given)

  • diag - the diagonal value

Output Parameter#

  • J - the diagonal matrix

Notes#

Only supports square matrices with the same number of local rows and columns

See Also#

Matrices, Mat, MatDestroy(), MATCONSTANTDIAGONAL, MatScale(), MatShift(), MatMult(), MatGetDiagonal(), MatGetFactor(), MatSolve()

Level#

advanced

Location#

src/mat/impls/cdiagonal/cdiagonal.c

Examples#

src/ksp/ksp/tutorials/ex27.c

Index of all Mat routines
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Index of all manual pages