MatSetValue#

Set a single entry into a matrix.

Synopsis#

Not Collective

Input Parameters#

  • mat - the matrix

  • i - the row location of the entry

  • j - the column location of the entry

  • va - the value to insert

  • mode - either INSERT_VALUES or ADD_VALUES

Notes#

This value may be cached, so MatAssemblyBegin() and MatAssemblyEnd() MUST be called after all calls to MatSetValue() have been completed.

For efficiency one should use MatSetValues() and set several values simultaneously.

See Also#

Matrices, Mat, MatAssemblyBegin(), MatAssemblyEnd(), InsertMode, MatGetValue(), MatSetValues(), MatSetValueLocal(), MatSetValuesLocal()

Level#

beginner

Location#

include/petscmat.h

Examples#

src/ts/tutorials/ex24.c
src/snes/tutorials/ex48.c
src/ts/tutorials/ex10.c
src/ts/tutorials/ex44.c
src/ts/tutorials/ex43.c
src/ksp/ksp/tutorials/ex59.c
src/ksp/ksp/tutorials/ex84.c
src/tao/tutorials/ex4.c
src/ts/tutorials/ex20opt_p.c
src/ksp/ksp/tutorials/ex21.c


Index of all Mat routines
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Index of all manual pages