Actual source code: ex32.c
petsc-3.6.1 2015-08-06
2: #include <petscmat.h>
4: #if !defined(PETSC_USE_64BIT_INDICES)
5: static char help[] = "Reads in a matrix and vector in ASCII slap format. Writes\n\
6: them using the PETSc sparse format. Input parameters are:\n\
7: -fin <filename> : input file\n\
8: -fout <filename> : output file\n\n";
9: #endif
13: int main(int argc,char **args)
14: {
15: #if !defined(PETSC_USE_64BIT_INDICES)
16: Mat A;
17: Vec b;
18: char filein[PETSC_MAX_PATH_LEN],fileout[PETSC_MAX_PATH_LEN];
19: PetscInt i,j,m,n,nnz,start,end,*col,*row,*brow,length;
21: PetscMPIInt size,rank;
22: PetscScalar *val,*bval;
23: FILE *file;
24: PetscViewer view;
25: PetscBool opt;
27: PetscInitialize(&argc,&args,(char*)0,help);
29: /* Read in matrix and RHS */
30: PetscOptionsGetString(NULL,"-fin",filein,PETSC_MAX_PATH_LEN,&opt);
31: if (!opt) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_ARG_WRONG, "No filename was specified for this test");
32: MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
33: MPI_Comm_size(PETSC_COMM_WORLD,&size);
35: PetscFOpen(PETSC_COMM_SELF,filein,"r",&file);
37: fscanf(file," NUNKNS =%d NCOEFF =%d\n",&n,&nnz);
38: fscanf(file," JA POINTER IN SLAPSV\n");
40: MatCreateSeqAIJ(PETSC_COMM_WORLD,n,n,20,0,&A);
41: VecCreate(PETSC_COMM_WORLD,&b);
42: VecSetSizes(b,PETSC_DECIDE,n);
43: VecSetFromOptions(b);
45: PetscMalloc1(n+1,&col);
46: for (i=0; i<n+1; i++) fscanf(file," I=%d%d\n",&j,&col[i]);
47: fscanf(file," EOD JA\n");
49: PetscMalloc1(nnz,&val);
50: PetscMalloc1(nnz,&row);
51: fscanf(file," COEFFICIENT MATRIX IN SLAPSV: I, IA, A\n");
52: for (i=0; i<nnz; i++) {
53: fscanf(file," %d%d%le\n",&j,&row[i],(double*)&val[i]);
54: row[i]--;
55: }
56: fscanf(file," EOD IA\n");
58: PetscMalloc1(n,&bval);
59: PetscMalloc1(n,&brow);
60: fscanf(file," RESIDUAL IN SLAPSV ;IRHS=%d\n",&j);
61: for (i=0; i<n; i++) {
62: fscanf(file," %d%le%d\n",&j,(double*)(bval+i),&j);
63: brow[i] = i;
64: }
65: fscanf(file," EOD RESIDUAL");
66: fclose(file);
68: m = n/size+1;
69: start = rank*m;
70: end = (rank+1)*m; if (end > n) end = n;
71: for (j=start; j<end; j++) {
72: length = col[j+1]-col[j];
73: MatSetValues(A,length,&row[col[j]-1],1,&j,&val[col[j]-1],INSERT_VALUES);
74: }
75: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
76: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
78: VecGetOwnershipRange(b,&start,&end);
79: VecSetValues(b,end-start,brow+start,bval+start,INSERT_VALUES);
80: VecAssemblyBegin(b);
81: VecAssemblyEnd(b);
83: PetscFree(col);
84: PetscFree(val);
85: PetscFree(row);
86: PetscFree(bval);
87: PetscFree(brow);
89: PetscPrintf(PETSC_COMM_SELF,"Reading matrix completes.\n");
90: PetscOptionsGetString(NULL,"-fout",fileout,PETSC_MAX_PATH_LEN,NULL);
91: PetscViewerBinaryOpen(PETSC_COMM_WORLD,fileout,FILE_MODE_WRITE,&view);
92: MatView(A,view);
93: VecView(b,view);
94: PetscViewerDestroy(&view);
96: VecDestroy(&b);
97: MatDestroy(&A);
99: PetscFinalize();
100: #endif
101: return 0;
102: }