PETSc version 3.16.5
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# VecSetValue

Set a single entry into a vector.

### Synopsis

    #include <petscvec.h>
    PetscErrorCode VecSetValue(Vec v,PetscInt row,PetscScalar value, InsertMode mode);

Not Collective

### Input Parameters

| v | - the vector
| row | - the row location of the entry
| value | - the value to insert
| mode | - either INSERT_VALUES or ADD_VALUES

### Notes

For efficiency one should use VecSetValues() and set several or many values simultaneously if possible.

These values may be cached, so VecAssemblyBegin() and VecAssemblyEnd() MUST be called after all calls to VecSetValue() have been completed.

VecSetValue() uses 0-based indices in Fortran as well as in C.

### See Also

VecSetValues(), VecAssemblyBegin(), VecAssemblyEnd(), VecSetValuesBlockedLocal(), VecSetValueLocal()

### Level

beginner

### Location

src/vec/vec/utils/tagger/../../../../../include/petscvec.h

### Examples

src/ksp/ksp/tutorials/ex43.c.html
src/ksp/ksp/tutorials/ex49.c.html
src/ksp/ksp/tutorials/ex56.c.html
src/snes/tutorials/ex28.c.html
src/snes/tutorials/ex30.c.html
src/snes/tutorials/ex56.c.html
src/snes/tutorials/ex70.c.html
src/ts/tutorials/extchem.c.html
src/ts/tutorials/extchemfield.c.html
src/tao/constrained/tutorials/ex1.c.html
Index of all Vec routines
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Index of all manual pages