xref: /petsc/src/mat/tests/ex195.c (revision ebead697dbf761eb322f829370bbe90b3bd93fa3)
1 /*
2  * ex195.c
3  *
4  *  Created on: Aug 24, 2015
5  *      Author: Fande Kong <fdkong.jd@gmail.com>
6  */
7 
8 static char help[] = " Demonstrate the use of MatConvert_Nest_AIJ\n";
9 
10 #include <petscmat.h>
11 
12 int main(int argc,char **args)
13 {
14   Mat                 A1,A2,A3,A4,A5,B,C,C1,nest;
15   Mat                 mata[4];
16   Mat                 aij;
17   MPI_Comm            comm;
18   PetscInt            m,M,n,istart,iend,ii,i,J,j,K=10;
19   PetscScalar         v;
20   PetscMPIInt         size;
21   PetscBool           equal;
22 
23   PetscFunctionBeginUser;
24   PetscCall(PetscInitialize(&argc,&args,(char*)0,help));
25   comm = PETSC_COMM_WORLD;
26   PetscCallMPI(MPI_Comm_size(comm,&size));
27 
28   /*
29      Assemble the matrix for the five point stencil, YET AGAIN
30   */
31   PetscCall(MatCreate(comm,&A1));
32   m=2,n=2;
33   PetscCall(MatSetSizes(A1,PETSC_DECIDE,PETSC_DECIDE,m*n,m*n));
34   PetscCall(MatSetFromOptions(A1));
35   PetscCall(MatSetUp(A1));
36   PetscCall(MatGetOwnershipRange(A1,&istart,&iend));
37   for (ii=istart; ii<iend; ii++) {
38     v = -1.0; i = ii/n; j = ii - i*n;
39     if (i>0)   {J = ii - n; PetscCall(MatSetValues(A1,1,&ii,1,&J,&v,INSERT_VALUES));}
40     if (i<m-1) {J = ii + n; PetscCall(MatSetValues(A1,1,&ii,1,&J,&v,INSERT_VALUES));}
41     if (j>0)   {J = ii - 1; PetscCall(MatSetValues(A1,1,&ii,1,&J,&v,INSERT_VALUES));}
42     if (j<n-1) {J = ii + 1; PetscCall(MatSetValues(A1,1,&ii,1,&J,&v,INSERT_VALUES));}
43     v = 4.0; PetscCall(MatSetValues(A1,1,&ii,1,&ii,&v,INSERT_VALUES));
44   }
45   PetscCall(MatAssemblyBegin(A1,MAT_FINAL_ASSEMBLY));
46   PetscCall(MatAssemblyEnd(A1,MAT_FINAL_ASSEMBLY));
47   PetscCall(MatView(A1,PETSC_VIEWER_STDOUT_WORLD));
48 
49   PetscCall(MatDuplicate(A1,MAT_COPY_VALUES,&A2));
50   PetscCall(MatDuplicate(A1,MAT_COPY_VALUES,&A3));
51   PetscCall(MatDuplicate(A1,MAT_COPY_VALUES,&A4));
52 
53   /*create a nest matrix */
54   PetscCall(MatCreate(comm,&nest));
55   PetscCall(MatSetType(nest,MATNEST));
56   mata[0]=A1,mata[1]=A2,mata[2]=A3,mata[3]=A4;
57   PetscCall(MatNestSetSubMats(nest,2,NULL,2,NULL,mata));
58   PetscCall(MatSetUp(nest));
59   PetscCall(MatConvert(nest,MATAIJ,MAT_INITIAL_MATRIX,&aij));
60   PetscCall(MatView(aij,PETSC_VIEWER_STDOUT_WORLD));
61 
62   /* create a dense matrix */
63   PetscCall(MatGetSize(nest,&M,NULL));
64   PetscCall(MatGetLocalSize(nest,&m,NULL));
65   PetscCall(MatCreateDense(comm,m,PETSC_DECIDE,M,K,NULL,&B));
66   PetscCall(MatSetRandom(B,PETSC_NULL));
67 
68   /* C = nest*B_dense */
69   PetscCall(MatMatMult(nest,B,MAT_INITIAL_MATRIX,PETSC_DEFAULT,&C));
70   PetscCall(MatMatMult(nest,B,MAT_REUSE_MATRIX,PETSC_DEFAULT,&C));
71   PetscCall(MatMatMultEqual(nest,B,C,10,&equal));
72   PetscCheck(equal,PETSC_COMM_WORLD,PETSC_ERR_PLIB,"Error in C != nest*B_dense");
73 
74   /* Test B = nest*C, reuse C and B with MatProductCreateWithMat() */
75   /* C has been obtained from nest*B. Clear internal data structures related to factors to prevent circular references */
76   PetscCall(MatProductClear(C));
77   PetscCall(MatProductCreateWithMat(nest,C,NULL,B));
78   PetscCall(MatProductSetType(B,MATPRODUCT_AB));
79   PetscCall(MatProductSetFromOptions(B));
80   PetscCall(MatProductSymbolic(B));
81   PetscCall(MatProductNumeric(B));
82   PetscCall(MatMatMultEqual(nest,C,B,10,&equal));
83   PetscCheck(equal,PETSC_COMM_WORLD,PETSC_ERR_PLIB,"Error in B != nest*C_dense");
84   PetscCall(MatConvert(nest,MATAIJ,MAT_INPLACE_MATRIX,&nest));
85   PetscCall(MatEqual(nest,aij,&equal));
86   PetscCheck(equal,PETSC_COMM_WORLD,PETSC_ERR_PLIB,"Error in aij != nest");
87   PetscCall(MatDestroy(&nest));
88 
89   if (size > 1) { /* Do not know why this test fails for size = 1 */
90     PetscCall(MatCreateTranspose(A1,&A5)); /* A1 is symmetric */
91     mata[0] = A5;
92     PetscCall(MatCreate(comm,&nest));
93     PetscCall(MatSetType(nest,MATNEST));
94     PetscCall(MatNestSetSubMats(nest,2,NULL,2,NULL,mata));
95     PetscCall(MatSetUp(nest));
96     PetscCall(MatMatMult(nest,B,MAT_INITIAL_MATRIX,PETSC_DEFAULT,&C1));
97     PetscCall(MatMatMult(nest,B,MAT_REUSE_MATRIX,PETSC_DEFAULT,&C1));
98 
99     PetscCall(MatMatMultEqual(nest,B,C1,10,&equal));
100     PetscCheck(equal,PETSC_COMM_WORLD,PETSC_ERR_PLIB,"Error in C1 != C");
101     PetscCall(MatDestroy(&C1));
102     PetscCall(MatDestroy(&A5));
103     PetscCall(MatDestroy(&nest));
104   }
105 
106   PetscCall(MatDestroy(&C));
107   PetscCall(MatDestroy(&B));
108   PetscCall(MatDestroy(&aij));
109   PetscCall(MatDestroy(&A1));
110   PetscCall(MatDestroy(&A2));
111   PetscCall(MatDestroy(&A3));
112   PetscCall(MatDestroy(&A4));
113   PetscCall(PetscFinalize());
114   return 0;
115 }
116 
117 /*TEST
118 
119    test:
120       nsize: 2
121 
122    test:
123       suffix: 2
124 
125 TEST*/
126