Clear row/column of a sparse matrix
Submitted by Christopher Batty
Assigned to Nobody
Clearing a row or column of a matrix (depending on the storage format) can sometimes be a useful operation in finite element/difference computations, such as in setting up Dirichlet boundary conditions. Using this method, you can build your matrix without regard for boundary conditions, and then in a second step replace the rows corresponding to known values with the identity.
PETSC, for example, supports this operation with the MatZeroRows command.