323     Vec          xt;  in MatZeroRows_Shell()  local
331     PetscCall(MatCreateVecs(mat, &xt, NULL));  in MatZeroRows_Shell()
332     PetscCall(VecCopy(x, xt));  in MatZeroRows_Shell()
334     PetscCall(VecSetValues(xt, nc, gcols, vals, INSERT_VALUES)); /* xt = [x1, 0] */  in MatZeroRows_Shell()
336     PetscCall(VecAssemblyBegin(xt));  in MatZeroRows_Shell()
337     PetscCall(VecAssemblyEnd(xt));  in MatZeroRows_Shell()
338     PetscCall(VecAYPX(xt, -1.0, x)); /* xt = [0, x2] */  in MatZeroRows_Shell()
340     PetscCall(VecGetOwnershipRange(xt, &st, NULL));  in MatZeroRows_Shell()
341     PetscCall(VecGetLocalSize(xt, &nl));  in MatZeroRows_Shell()
342     PetscCall(VecGetArray(xt, &vals));  in MatZeroRows_Shell()
349     PetscCall(VecRestoreArray(xt, &vals));  in MatZeroRows_Shell()
352     PetscCall(VecDestroy(&xt));  in MatZeroRows_Shell()
371     Vec          xt, bt;  in MatZeroRowsColumns_Shell()  local
382     PetscCall(MatCreateVecs(mat, &xt, &bt));  in MatZeroRowsColumns_Shell()
383     PetscCall(VecCopy(x, xt));  in MatZeroRowsColumns_Shell()
384     PetscCall(VecSetValues(xt, nc, gcols, vals, INSERT_VALUES)); /* xt = [x1, 0] */  in MatZeroRowsColumns_Shell()
385     PetscCall(VecAssemblyBegin(xt));  in MatZeroRowsColumns_Shell()
386     PetscCall(VecAssemblyEnd(xt));  in MatZeroRowsColumns_Shell()
387     PetscCall(VecAXPY(xt, -1.0, x));                             /* xt = [0, -x2] */  in MatZeroRowsColumns_Shell()
388     PetscCall(MatMult(mat, xt, bt));                             /* bt = [-A12*x2,-A22*x2] */  in MatZeroRowsColumns_Shell()
398     PetscCall(VecGetOwnershipRange(xt, &st, NULL));  in MatZeroRowsColumns_Shell()
399     PetscCall(VecGetLocalSize(xt, &nl));  in MatZeroRowsColumns_Shell()
400     PetscCall(VecGetArray(xt, &vals));  in MatZeroRowsColumns_Shell()
407     PetscCall(VecRestoreArray(xt, &vals));  in MatZeroRowsColumns_Shell()
410     PetscCall(VecDestroy(&xt));  in MatZeroRowsColumns_Shell()