Actual source code: ex78.c
petsc-3.3-p6 2013-02-11
2: static char help[] = "Reads in a matrix in ASCII MATLAB format (I,J,A), read in vectors rhs and exact_solu in ASCII format.\n\
3: Writes them using the PETSc sparse format.\n\
4: Note: I and J start at 1, not 0, use -noshift if indices in file start with zero!\n\
5: Input parameters are:\n\
6: -Ain <filename> : input matrix in ascii format\n\
7: -rhs <filename> : input rhs in ascii format\n\
8: -solu <filename> : input true solution in ascii format\n\\n";
10: /*
11: Example: ./ex78 -Ain Ain -rhs rhs -solu solu -noshift -mat_view
12: with the datafiles in the followig format:
13: Ain (I and J start at 0):
14: ------------------------
15: 3 3 6
16: 0 0 1.0
17: 0 1 2.0
18: 1 0 3.0
19: 1 1 4.0
20: 1 2 5.0
21: 2 2 6.0
23: rhs
24: ---
25: 0 3.0
26: 1 12.0
27: 2 6.0
29: solu
30: ----
31: 0 1.0
32: 0 1.0
33: 0 1.0
34: */
36: #include <petscmat.h>
40: int main(int argc,char **args)
41: {
42: Mat A;
43: Vec b,u,u_tmp;
44: char Ain[PETSC_MAX_PATH_LEN],rhs[PETSC_MAX_PATH_LEN],solu[PETSC_MAX_PATH_LEN];
46: int m,n,nz,dummy; /* these are fscaned so kept as int */
47: PetscInt i,col,row,shift = 1,sizes[3],nsizes;
48: PetscScalar val;
49: PetscReal res_norm;
50: FILE *Afile,*bfile,*ufile;
51: PetscViewer view;
52: PetscBool flg_A,flg_b,flg_u,flg;
53: PetscMPIInt size;
55: PetscInitialize(&argc,&args,(char *)0,help);
56: MPI_Comm_size(PETSC_COMM_WORLD,&size);
57: if (size != 1) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_SUP,"This is a uniprocessor example only!");
59: /* Read in matrix, rhs and exact solution from ascii files */
60: PetscOptionsGetString(PETSC_NULL,"-Ain",Ain,PETSC_MAX_PATH_LEN,&flg_A);
61: PetscOptionsHasName(PETSC_NULL,"-noshift",&flg);
62: if (flg) shift = 0;
63: if (flg_A){
64: PetscPrintf(PETSC_COMM_SELF,"\n Read matrix in ascii format ...\n");
65: PetscFOpen(PETSC_COMM_SELF,Ain,"r",&Afile);
66: nsizes = 3;
67: PetscOptionsGetIntArray(PETSC_NULL,"-nosizesinfile",sizes,&nsizes,&flg);
68: if (flg) {
69: if (nsizes != 3) SETERRQ(PETSC_COMM_WORLD,1,"Must pass in three m,n,nz as arguments for -nosizesinfile");
70: m = sizes[0];
71: n = sizes[1];
72: nz = sizes[2];
73: } else {
74: fscanf(Afile,"%d %d %d\n",&m,&n,&nz);
75: }
76: PetscPrintf(PETSC_COMM_SELF,"m: %d, n: %d, nz: %d \n", m,n,nz);
77: if (m != n) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ, "Number of rows, cols must be same for this example\n");
78: MatCreate(PETSC_COMM_SELF,&A);
79: MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,m,n);
80: MatSetFromOptions(A);
81: MatSeqAIJSetPreallocation(A,nz/m,PETSC_NULL);
83: for (i=0; i<nz; i++) {
84: fscanf(Afile,"%d %d %le\n",&row,&col,(double*)&val);
85: row -= shift; col -= shift; /* set index set starts at 0 */
86: MatSetValues(A,1,&row,1,&col,&val,INSERT_VALUES);
87: }
88: MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
89: MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
90: fflush(stdout);
91: fclose(Afile);
92: }
94: PetscOptionsGetString(PETSC_NULL,"-rhs",rhs,PETSC_MAX_PATH_LEN,&flg_b);
95: if (flg_b){
96: VecCreate(PETSC_COMM_SELF,&b);
97: VecSetSizes(b,PETSC_DECIDE,n);
98: VecSetFromOptions(b);
99: PetscPrintf(PETSC_COMM_SELF,"\n Read rhs in ascii format ...\n");
100: PetscFOpen(PETSC_COMM_SELF,rhs,"r",&bfile);
101: for (i=0; i<n; i++) {
102: fscanf(bfile,"%d %le\n",&dummy,(double*)&val);
103: VecSetValues(b,1,&i,&val,INSERT_VALUES);
104: }
105: VecAssemblyBegin(b);
106: VecAssemblyEnd(b);
107: fflush(stdout);
108: fclose(bfile);
109: }
111: PetscOptionsGetString(PETSC_NULL,"-solu",solu,PETSC_MAX_PATH_LEN,&flg_u);
112: if (flg_u){
113: VecCreate(PETSC_COMM_SELF,&u);
114: VecSetSizes(u,PETSC_DECIDE,n);
115: VecSetFromOptions(u);
116: PetscPrintf(PETSC_COMM_SELF,"\n Read exact solution in ascii format ...\n");
117: PetscFOpen(PETSC_COMM_SELF,solu,"r",&ufile);
118: for (i=0; i<n; i++) {
119: fscanf(ufile,"%d %le\n",&dummy,(double*)&val);
120: VecSetValues(u,1,&i,&val,INSERT_VALUES);
121: }
122: VecAssemblyBegin(u);
123: VecAssemblyEnd(u);
124: fflush(stdout);
125: fclose(ufile);
126: }
127:
128: /* Write matrix, rhs and exact solution in Petsc binary file */
129: PetscPrintf(PETSC_COMM_SELF,"\n Write matrix in binary to 'matrix.dat' ...\n");
130: PetscViewerBinaryOpen(PETSC_COMM_SELF,"matrix.dat",FILE_MODE_WRITE,&view);
131: MatView(A,view);
133: if (flg_b){ /* Write rhs in Petsc binary file */
134: PetscPrintf(PETSC_COMM_SELF,"\n Write rhs in binary to 'matrix.dat' ...\n");
135: VecView(b,view);
136: }
137: if (flg_u){
138: PetscPrintf(PETSC_COMM_SELF,"\n Write exact solution in binary to 'matrix.dat' ...\n");
139: VecView(u,view);
140: }
142: /* Check accuracy of the data */
143: if (flg_A & flg_b & flg_u){
144: VecDuplicate(u,&u_tmp);
145: MatMult(A,u,u_tmp);
146: VecAXPY(u_tmp,-1.0,b);
147: VecNorm(u_tmp,NORM_2,&res_norm);
148: PetscPrintf(PETSC_COMM_SELF,"\n Accuracy of the reading data: | b - A*u |_2 : %g \n",res_norm);
149: VecDestroy(&u_tmp);
150: }
152: MatDestroy(&A);
153: if (flg_b) {VecDestroy(&b);}
154: if (flg_u) {VecDestroy(&u);}
155: PetscViewerDestroy(&view);
156: PetscFinalize();
157: return 0;
158: }