xref: /petsc/src/mat/tests/ex78.c (revision d5b43468fb8780a8feea140ccd6fa3e6a50411cc)
1 
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";
9 
10 /*
11 Example: ./ex78 -Ain Ain -rhs rhs -solu solu -noshift -mat_view
12  with the datafiles in the following 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
22 
23 rhs
24 ---
25 0 3.0
26 1 12.0
27 2 6.0
28 
29 solu
30 ----
31 0 1.0
32 0 1.0
33 0 1.0
34 */
35 
36 #include <petscmat.h>
37 
38 int main(int argc, char **args)
39 {
40   Mat         A = NULL;
41   Vec         b, u = NULL, u_tmp;
42   char        Ain[PETSC_MAX_PATH_LEN], rhs[PETSC_MAX_PATH_LEN], solu[PETSC_MAX_PATH_LEN];
43   int         m, n = 0, nz, dummy; /* these are fscaned so kept as int */
44   PetscInt    i, col, row, shift = 1, sizes[3], nsizes;
45   PetscScalar val;
46   PetscReal   res_norm;
47   FILE       *Afile, *bfile, *ufile;
48   PetscViewer view;
49   PetscBool   flg_A, flg_b, flg_u, flg;
50   PetscMPIInt size;
51 
52   PetscFunctionBeginUser;
53   PetscCall(PetscInitialize(&argc, &args, (char *)0, help));
54   PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size));
55   PetscCheck(size == 1, PETSC_COMM_WORLD, PETSC_ERR_WRONG_MPI_SIZE, "This is a uniprocessor example only!");
56 
57   /* Read in matrix, rhs and exact solution from ascii files */
58   PetscCall(PetscOptionsGetString(NULL, NULL, "-Ain", Ain, sizeof(Ain), &flg_A));
59   PetscCall(PetscOptionsHasName(NULL, NULL, "-noshift", &flg));
60   if (flg) shift = 0;
61   if (flg_A) {
62     PetscCall(PetscPrintf(PETSC_COMM_SELF, "\n Read matrix in ascii format ...\n"));
63     PetscCall(PetscFOpen(PETSC_COMM_SELF, Ain, "r", &Afile));
64     nsizes = 3;
65     PetscCall(PetscOptionsGetIntArray(NULL, NULL, "-nosizesinfile", sizes, &nsizes, &flg));
66     if (flg) {
67       PetscCheck(nsizes == 3, PETSC_COMM_WORLD, PETSC_ERR_USER, "Must pass in three m,n,nz as arguments for -nosizesinfile");
68       m  = sizes[0];
69       n  = sizes[1];
70       nz = sizes[2];
71     } else {
72       PetscCheck(fscanf(Afile, "%d %d %d\n", &m, &n, &nz) == 3, PETSC_COMM_SELF, PETSC_ERR_FILE_UNEXPECTED, "Badly formatted input file");
73     }
74     PetscCall(PetscPrintf(PETSC_COMM_SELF, "m: %d, n: %d, nz: %d \n", m, n, nz));
75     PetscCheck(m == n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Number of rows, cols must be same for this example");
76     PetscCall(MatCreate(PETSC_COMM_SELF, &A));
77     PetscCall(MatSetSizes(A, PETSC_DECIDE, PETSC_DECIDE, m, n));
78     PetscCall(MatSetFromOptions(A));
79     PetscCall(MatSeqAIJSetPreallocation(A, nz / m, NULL));
80     PetscCall(MatSetOption(A, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE));
81 
82     for (i = 0; i < nz; i++) {
83       PetscCheck(fscanf(Afile, "%d %d %le\n", &row, &col, (double *)&val) == 3, PETSC_COMM_SELF, PETSC_ERR_FILE_UNEXPECTED, "Badly formatted input file");
84       row -= shift;
85       col -= shift; /* set index set starts at 0 */
86       PetscCall(MatSetValues(A, 1, &row, 1, &col, &val, INSERT_VALUES));
87     }
88     PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
89     PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
90     fclose(Afile);
91   }
92 
93   PetscCall(PetscOptionsGetString(NULL, NULL, "-rhs", rhs, sizeof(rhs), &flg_b));
94   if (flg_b) {
95     PetscCall(VecCreate(PETSC_COMM_SELF, &b));
96     PetscCall(VecSetSizes(b, PETSC_DECIDE, n));
97     PetscCall(VecSetFromOptions(b));
98     PetscCall(PetscPrintf(PETSC_COMM_SELF, "\n Read rhs in ascii format ...\n"));
99     PetscCall(PetscFOpen(PETSC_COMM_SELF, rhs, "r", &bfile));
100     for (i = 0; i < n; i++) {
101       PetscCheck(fscanf(bfile, "%d %le\n", &dummy, (double *)&val) == 2, PETSC_COMM_SELF, PETSC_ERR_FILE_UNEXPECTED, "Badly formatted input file");
102       PetscCall(VecSetValues(b, 1, &i, &val, INSERT_VALUES));
103     }
104     PetscCall(VecAssemblyBegin(b));
105     PetscCall(VecAssemblyEnd(b));
106     fclose(bfile);
107   }
108 
109   PetscCall(PetscOptionsGetString(NULL, NULL, "-solu", solu, sizeof(solu), &flg_u));
110   if (flg_u) {
111     PetscCall(VecCreate(PETSC_COMM_SELF, &u));
112     PetscCall(VecSetSizes(u, PETSC_DECIDE, n));
113     PetscCall(VecSetFromOptions(u));
114     PetscCall(PetscPrintf(PETSC_COMM_SELF, "\n Read exact solution in ascii format ...\n"));
115     PetscCall(PetscFOpen(PETSC_COMM_SELF, solu, "r", &ufile));
116     for (i = 0; i < n; i++) {
117       PetscCheck(fscanf(ufile, "%d  %le\n", &dummy, (double *)&val) == 2, PETSC_COMM_SELF, PETSC_ERR_FILE_UNEXPECTED, "Badly formatted input file");
118       PetscCall(VecSetValues(u, 1, &i, &val, INSERT_VALUES));
119     }
120     PetscCall(VecAssemblyBegin(u));
121     PetscCall(VecAssemblyEnd(u));
122     fclose(ufile);
123   }
124 
125   /* Write matrix, rhs and exact solution in Petsc binary file */
126   PetscCall(PetscPrintf(PETSC_COMM_SELF, "\n Write matrix in binary to 'matrix.dat' ...\n"));
127   PetscCall(PetscViewerBinaryOpen(PETSC_COMM_SELF, "matrix.dat", FILE_MODE_WRITE, &view));
128   PetscCall(MatView(A, view));
129 
130   if (flg_b) { /* Write rhs in Petsc binary file */
131     PetscCall(PetscPrintf(PETSC_COMM_SELF, "\n Write rhs in binary to 'matrix.dat' ...\n"));
132     PetscCall(VecView(b, view));
133   }
134   if (flg_u) {
135     PetscCall(PetscPrintf(PETSC_COMM_SELF, "\n Write exact solution in binary to 'matrix.dat' ...\n"));
136     PetscCall(VecView(u, view));
137   }
138 
139   /* Check accuracy of the data */
140   if (flg_A & flg_b & flg_u) {
141     PetscCall(VecDuplicate(u, &u_tmp));
142     PetscCall(MatMult(A, u, u_tmp));
143     PetscCall(VecAXPY(u_tmp, -1.0, b));
144     PetscCall(VecNorm(u_tmp, NORM_2, &res_norm));
145     PetscCall(PetscPrintf(PETSC_COMM_SELF, "\n Accuracy of the reading data: | b - A*u |_2 : %g \n", res_norm));
146     PetscCall(VecDestroy(&u_tmp));
147   }
148 
149   PetscCall(MatDestroy(&A));
150   if (flg_b) PetscCall(VecDestroy(&b));
151   if (flg_u) PetscCall(VecDestroy(&u));
152   PetscCall(PetscViewerDestroy(&view));
153   PetscCall(PetscFinalize());
154   return 0;
155 }
156 
157 /*TEST
158 
159    build:
160       requires:  !defined(PETSC_USE_64BIT_INDICES) double !complex
161 
162    test:
163       requires: datafilespath
164       args: -Ain ${DATAFILESPATH}/matrices/indefinite/afiro_A.dat
165 
166 TEST*/
167