MatSetValues#
Inserts or adds a block of values into a matrix. These values may be cached, so MatAssemblyBegin() and MatAssemblyEnd() MUST be called after all calls to MatSetValues() have been completed.
Synopsis#
#include "petscmat.h"
PetscErrorCode MatSetValues(Mat mat, PetscInt m, const PetscInt idxm[], PetscInt n, const PetscInt idxn[], const PetscScalar v[], InsertMode addv)
Not Collective
Input Parameters#
mat - the matrix
v - a logically two-dimensional array of values
m - the number of rows
idxm - the global indices of the rows
n - the number of columns
idxn - the global indices of the columns
addv - either
ADD_VALUESto add values to any existing entries, orINSERT_VALUESto replace existing entries with new values
Notes#
By default the values, v, are stored row-oriented. See MatSetOption() for other options.
Calls to MatSetValues() with the INSERT_VALUES and ADD_VALUES
options cannot be mixed without intervening calls to the assembly
routines.
MatSetValues() uses 0-based row and column numbers in Fortran
as well as in C.
Negative indices may be passed in idxm and idxn, these rows and columns are
simply ignored. This allows easily inserting element stiffness matrices
with homogeneous Dirichlet boundary conditions that you don’t want represented
in the matrix.
Efficiency Alert#
The routine MatSetValuesBlocked() may offer much better efficiency
for users of block sparse formats (MATSEQBAIJ and MATMPIBAIJ).
Fortran Notes#
If any of idxm, idxn, and v are scalars pass them using, for example,
MatSetValues(mat, one, [idxm], one, [idxn], [v], INSERT_VALUES)
If v is a two-dimensional array use reshape() to pass it as a one dimensional array
Developer Note#
This is labeled with C so does not automatically generate Fortran stubs and interfaces because it requires multiple Fortran interfaces depending on which arguments are scalar or arrays.
See Also#
Matrices, Mat, MatSetOption(), MatAssemblyBegin(), MatAssemblyEnd(), MatSetValuesBlocked(), MatSetValuesLocal(),
InsertMode, INSERT_VALUES, ADD_VALUES
Level#
beginner
Location#
Examples#
src/mat/tutorials/ex3.c
src/mat/tutorials/ex17f.F90
src/mat/tutorials/ex15f.F90
src/mat/tutorials/ex12.c
src/mat/tutorials/ex18.c
src/mat/tutorials/ex16.c
src/mat/tutorials/ex15.c
src/mat/tutorials/ex8.c
src/mat/tutorials/ex2.c
src/mat/tutorials/ex17.c
Implementations#
MatSetValues_MPIAdj() in src/mat/impls/adj/mpi/mpiadj.c
MatSetValues_MPIAIJ() in src/mat/impls/aij/mpi/mpiaij.c
MatSetValues_SeqAIJ() in src/mat/impls/aij/seq/aij.c
MatSetValues_MPIBAIJ() in src/mat/impls/baij/mpi/mpibaij.c
MatSetValues_SeqBAIJ() in src/mat/impls/baij/seq/baij.c
MatSetValues_BlockMat() in src/mat/impls/blockmat/seq/blockmat.c
MatSetValues_MPIDense() in src/mat/impls/dense/mpi/mpidense.c
MatSetValues_SeqDense() in src/mat/impls/dense/seq/dense.c
MatSetValues_Elemental() in src/mat/impls/elemental/matelem.cxx
MatSetValues_HYPRE() in src/mat/impls/hypre/mhypre.c
MatSetValues_IS() in src/mat/impls/is/matis.c
MatSetValues_Preallocator() in src/mat/impls/preallocator/matpreallocator.c
MatSetValues_MPISBAIJ() in src/mat/impls/sbaij/mpi/mpisbaij.c
MatSetValues_SeqSBAIJ() in src/mat/impls/sbaij/seq/sbaij.c
MatSetValues_ScaLAPACK() in src/mat/impls/scalapack/matscalapack.c
MatSetValues_MPISELL() in src/mat/impls/sell/mpi/mpisell.c
MatSetValues_SeqSELL() in src/mat/impls/sell/seq/sell.c
Index of all Mat routines
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Index of all manual pages