xref: /petsc/src/mat/tests/ex195.c (revision 503c0ea9b45bcfbcebbb1ea5341243bbc69f0bea)
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   PetscCall(PetscInitialize(&argc,&args,(char*)0,help));
24   comm = PETSC_COMM_WORLD;
25   PetscCallMPI(MPI_Comm_size(comm,&size));
26 
27   /*
28      Assemble the matrix for the five point stencil, YET AGAIN
29   */
30   PetscCall(MatCreate(comm,&A1));
31   m=2,n=2;
32   PetscCall(MatSetSizes(A1,PETSC_DECIDE,PETSC_DECIDE,m*n,m*n));
33   PetscCall(MatSetFromOptions(A1));
34   PetscCall(MatSetUp(A1));
35   PetscCall(MatGetOwnershipRange(A1,&istart,&iend));
36   for (ii=istart; ii<iend; ii++) {
37     v = -1.0; i = ii/n; j = ii - i*n;
38     if (i>0)   {J = ii - n; PetscCall(MatSetValues(A1,1,&ii,1,&J,&v,INSERT_VALUES));}
39     if (i<m-1) {J = ii + n; PetscCall(MatSetValues(A1,1,&ii,1,&J,&v,INSERT_VALUES));}
40     if (j>0)   {J = ii - 1; PetscCall(MatSetValues(A1,1,&ii,1,&J,&v,INSERT_VALUES));}
41     if (j<n-1) {J = ii + 1; PetscCall(MatSetValues(A1,1,&ii,1,&J,&v,INSERT_VALUES));}
42     v = 4.0; PetscCall(MatSetValues(A1,1,&ii,1,&ii,&v,INSERT_VALUES));
43   }
44   PetscCall(MatAssemblyBegin(A1,MAT_FINAL_ASSEMBLY));
45   PetscCall(MatAssemblyEnd(A1,MAT_FINAL_ASSEMBLY));
46   PetscCall(MatView(A1,PETSC_VIEWER_STDOUT_WORLD));
47 
48   PetscCall(MatDuplicate(A1,MAT_COPY_VALUES,&A2));
49   PetscCall(MatDuplicate(A1,MAT_COPY_VALUES,&A3));
50   PetscCall(MatDuplicate(A1,MAT_COPY_VALUES,&A4));
51 
52   /*create a nest matrix */
53   PetscCall(MatCreate(comm,&nest));
54   PetscCall(MatSetType(nest,MATNEST));
55   mata[0]=A1,mata[1]=A2,mata[2]=A3,mata[3]=A4;
56   PetscCall(MatNestSetSubMats(nest,2,NULL,2,NULL,mata));
57   PetscCall(MatSetUp(nest));
58   PetscCall(MatConvert(nest,MATAIJ,MAT_INITIAL_MATRIX,&aij));
59   PetscCall(MatView(aij,PETSC_VIEWER_STDOUT_WORLD));
60 
61   /* create a dense matrix */
62   PetscCall(MatGetSize(nest,&M,NULL));
63   PetscCall(MatGetLocalSize(nest,&m,NULL));
64   PetscCall(MatCreateDense(comm,m,PETSC_DECIDE,M,K,NULL,&B));
65   PetscCall(MatSetRandom(B,PETSC_NULL));
66   PetscCall(MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY));
67   PetscCall(MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY));
68 
69   /* C = nest*B_dense */
70   PetscCall(MatMatMult(nest,B,MAT_INITIAL_MATRIX,PETSC_DEFAULT,&C));
71   PetscCall(MatMatMult(nest,B,MAT_REUSE_MATRIX,PETSC_DEFAULT,&C));
72   PetscCall(MatMatMultEqual(nest,B,C,10,&equal));
73   PetscCheck(equal,PETSC_COMM_WORLD,PETSC_ERR_PLIB,"Error in C != nest*B_dense");
74 
75   /* Test B = nest*C, reuse C and B with MatProductCreateWithMat() */
76   /* C has been obtained from nest*B. Clear internal data structures related to factors to prevent circular references */
77   PetscCall(MatProductClear(C));
78   PetscCall(MatProductCreateWithMat(nest,C,NULL,B));
79   PetscCall(MatProductSetType(B,MATPRODUCT_AB));
80   PetscCall(MatProductSetFromOptions(B));
81   PetscCall(MatProductSymbolic(B));
82   PetscCall(MatProductNumeric(B));
83   PetscCall(MatMatMultEqual(nest,C,B,10,&equal));
84   PetscCheck(equal,PETSC_COMM_WORLD,PETSC_ERR_PLIB,"Error in B != nest*C_dense");
85   PetscCall(MatConvert(nest,MATAIJ,MAT_INPLACE_MATRIX,&nest));
86   PetscCall(MatEqual(nest,aij,&equal));
87   PetscCheck(equal,PETSC_COMM_WORLD,PETSC_ERR_PLIB,"Error in aij != nest");
88   PetscCall(MatDestroy(&nest));
89 
90   if (size > 1) { /* Do not know why this test fails for size = 1 */
91     PetscCall(MatCreateTranspose(A1,&A5)); /* A1 is symmetric */
92     mata[0] = A5;
93     PetscCall(MatCreate(comm,&nest));
94     PetscCall(MatSetType(nest,MATNEST));
95     PetscCall(MatNestSetSubMats(nest,2,NULL,2,NULL,mata));
96     PetscCall(MatSetUp(nest));
97     PetscCall(MatMatMult(nest,B,MAT_INITIAL_MATRIX,PETSC_DEFAULT,&C1));
98     PetscCall(MatMatMult(nest,B,MAT_REUSE_MATRIX,PETSC_DEFAULT,&C1));
99 
100     PetscCall(MatMatMultEqual(nest,B,C1,10,&equal));
101     PetscCheck(equal,PETSC_COMM_WORLD,PETSC_ERR_PLIB,"Error in C1 != C");
102     PetscCall(MatDestroy(&C1));
103     PetscCall(MatDestroy(&A5));
104     PetscCall(MatDestroy(&nest));
105   }
106 
107   PetscCall(MatDestroy(&C));
108   PetscCall(MatDestroy(&B));
109   PetscCall(MatDestroy(&aij));
110   PetscCall(MatDestroy(&A1));
111   PetscCall(MatDestroy(&A2));
112   PetscCall(MatDestroy(&A3));
113   PetscCall(MatDestroy(&A4));
114   PetscCall(PetscFinalize());
115   return 0;
116 }
117 
118 /*TEST
119 
120    test:
121       nsize: 2
122 
123    test:
124       suffix: 2
125 
126 TEST*/
127