VecSetValue

Set a single entry into a vector.

int VecSetValue(Vec v,int row,PetscScalar value, InsertMode mode);

Not Collective

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

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

Note that VecSetValue() does NOT return an error code (since this is checked internally).

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

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