#include "petscmat.h" PetscErrorCode MatZeroRowsStencil(Mat mat,PetscInt numRows,const MatStencil rows[],PetscScalar diag,Vec x,Vec b)Collective on Mat Many br
mat | - the matrix Many br | |
numRows | - the number of rows to remove Many br | |
rows | - the grid coordinates (and component number when dof > 1) for matrix rows Many br | |
diag | - value put in all diagonals of eliminated rows (0.0 will even eliminate diagonal entry) Many br | |
x | - optional vector of solutions for zeroed rows (other entries in vector are not used) Many br | |
b | - optional vector of right hand side, that will be adjusted by provided solution Many br |
If the option MatSetOption(mat,MAT_KEEP_NONZERO_PATTERN,PETSC_TRUE) the nonzero structure Many brof the matrix is not changed (even for AIJ and BAIJ matrices) the values are Many brmerely zeroed. Many br
The user can set a value in the diagonal entry (or for the AIJ and Many brrow formats can optionally remove the main diagonal entry from the Many brnonzero structure as well, by passing 0.0 as the final argument). Many br
For the parallel case, all processes that share the matrix (i.e., Many brthose in the communicator used for matrix creation) MUST call this Many brroutine, regardless of whether any rows being zeroed are owned by Many brthem. Many br
Each processor can indicate any rows in the entire matrix to be zeroed (i.e. each process does NOT have to Many brlist only rows local to itself). Many br
The grid coordinates are across the entire grid, not just the local portion Many br
In Fortran idxm and idxn should be declared as Many br
MatStencil idxm(4,m)and the values inserted using Many br
idxm(MatStencil_i,1) = i
idxm(MatStencil_j,1) = j
idxm(MatStencil_k,1) = k
idxm(MatStencil_c,1) = cetc Many br
For periodic boundary conditions use negative indices for values to the left (below 0; that are to be Many brobtained by wrapping values from right edge). For values to the right of the last entry using that index plus one Many bretc to obtain values that obtained by wrapping the values from the left edge. This does not work for anything but the Many brDM_BOUNDARY_PERIODIC boundary type. Many br
For indices that don't mean anything for your case (like the k index when working in 2d) or the c index when you have Many bra single value per point) you can skip filling those indices. Many br
Many br
Level:intermediate
Location:src/mat/interface/matrix.c
Index of all Mat routines
Table of Contents for all manual pages
Index of all manual pages