static char help[] = "Writes a matrix using the PETSc sparse format. Input arguments are:\n\ -fout : output file name\n\n"; #include "petscmat.h" #undef __FUNCT__ #define __FUNCT__ "main" int main(int argc,char **args) { Mat A; Vec b; char fileout[PETSC_MAX_PATH_LEN]; PetscInt i,j,m = 6,n = 6,N = 36,Ii,J; PetscErrorCode ierr; PetscScalar val,v; PetscViewer view; PetscInitialize(&argc,&args,(char *)0,help); ierr = MatCreate(PETSC_COMM_WORLD,&A);CHKERRQ(ierr); ierr = MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,N,N);CHKERRQ(ierr); ierr = MatSetFromOptions(A);CHKERRQ(ierr); for (i=0; i0) {J = Ii - n; ierr = MatSetValues(A,1,&Ii,1,&J,&v,INSERT_VALUES);CHKERRQ(ierr);} if (i0) {J = Ii - 1; ierr = MatSetValues(A,1,&Ii,1,&J,&v,INSERT_VALUES);CHKERRQ(ierr);} if (j