xref: /petsc/src/mat/tests/ex78.c (revision ebead697dbf761eb322f829370bbe90b3bd93fa3)
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; col -= shift;  /* set index set starts at 0 */
85       PetscCall(MatSetValues(A,1,&row,1,&col,&val,INSERT_VALUES));
86     }
87     PetscCall(MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY));
88     PetscCall(MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY));
89     fclose(Afile);
90   }
91 
92   PetscCall(PetscOptionsGetString(NULL,NULL,"-rhs",rhs,sizeof(rhs),&flg_b));
93   if (flg_b) {
94     PetscCall(VecCreate(PETSC_COMM_SELF,&b));
95     PetscCall(VecSetSizes(b,PETSC_DECIDE,n));
96     PetscCall(VecSetFromOptions(b));
97     PetscCall(PetscPrintf(PETSC_COMM_SELF,"\n Read rhs in ascii format ...\n"));
98     PetscCall(PetscFOpen(PETSC_COMM_SELF,rhs,"r",&bfile));
99     for (i=0; i<n; i++) {
100       PetscCheck(fscanf(bfile,"%d %le\n",&dummy,(double*)&val) == 2,PETSC_COMM_SELF,PETSC_ERR_FILE_UNEXPECTED,"Badly formatted input file");
101       PetscCall(VecSetValues(b,1,&i,&val,INSERT_VALUES));
102     }
103     PetscCall(VecAssemblyBegin(b));
104     PetscCall(VecAssemblyEnd(b));
105     fclose(bfile);
106   }
107 
108   PetscCall(PetscOptionsGetString(NULL,NULL,"-solu",solu,sizeof(solu),&flg_u));
109   if (flg_u) {
110     PetscCall(VecCreate(PETSC_COMM_SELF,&u));
111     PetscCall(VecSetSizes(u,PETSC_DECIDE,n));
112     PetscCall(VecSetFromOptions(u));
113     PetscCall(PetscPrintf(PETSC_COMM_SELF,"\n Read exact solution in ascii format ...\n"));
114     PetscCall(PetscFOpen(PETSC_COMM_SELF,solu,"r",&ufile));
115     for (i=0; i<n; i++) {
116       PetscCheck(fscanf(ufile,"%d  %le\n",&dummy,(double*)&val) == 2,PETSC_COMM_SELF,PETSC_ERR_FILE_UNEXPECTED,"Badly formatted input file");
117       PetscCall(VecSetValues(u,1,&i,&val,INSERT_VALUES));
118     }
119     PetscCall(VecAssemblyBegin(u));
120     PetscCall(VecAssemblyEnd(u));
121     fclose(ufile);
122   }
123 
124   /* Write matrix, rhs and exact solution in Petsc binary file */
125   PetscCall(PetscPrintf(PETSC_COMM_SELF,"\n Write matrix in binary to 'matrix.dat' ...\n"));
126   PetscCall(PetscViewerBinaryOpen(PETSC_COMM_SELF,"matrix.dat",FILE_MODE_WRITE,&view));
127   PetscCall(MatView(A,view));
128 
129   if (flg_b) { /* Write rhs in Petsc binary file */
130     PetscCall(PetscPrintf(PETSC_COMM_SELF,"\n Write rhs in binary to 'matrix.dat' ...\n"));
131     PetscCall(VecView(b,view));
132   }
133   if (flg_u) {
134     PetscCall(PetscPrintf(PETSC_COMM_SELF,"\n Write exact solution in binary to 'matrix.dat' ...\n"));
135     PetscCall(VecView(u,view));
136   }
137 
138   /* Check accuracy of the data */
139   if (flg_A & flg_b & flg_u) {
140     PetscCall(VecDuplicate(u,&u_tmp));
141     PetscCall(MatMult(A,u,u_tmp));
142     PetscCall(VecAXPY(u_tmp,-1.0,b));
143     PetscCall(VecNorm(u_tmp,NORM_2,&res_norm));
144     PetscCall(PetscPrintf(PETSC_COMM_SELF,"\n Accuracy of the reading data: | b - A*u |_2 : %g \n",res_norm));
145     PetscCall(VecDestroy(&u_tmp));
146   }
147 
148   PetscCall(MatDestroy(&A));
149   if (flg_b) PetscCall(VecDestroy(&b));
150   if (flg_u) PetscCall(VecDestroy(&u));
151   PetscCall(PetscViewerDestroy(&view));
152   PetscCall(PetscFinalize());
153   return 0;
154 }
155 
156 /*TEST
157 
158    build:
159       requires:  !defined(PETSC_USE_64BIT_INDICES) double !complex
160 
161    test:
162       requires: datafilespath
163       args: -Ain ${DATAFILESPATH}/matrices/indefinite/afiro_A.dat
164 
165 TEST*/
166