Actual source code: ex195.c

  1: /*
  2:  * ex195.c
  3:  *
  4:  *  Created on: Aug 24, 2015
  5:  *      Author: Fande Kong <fdkong.jd@gmail.com>
  6:  */

  8: static char help[] = " Demonstrate the use of MatConvert_Nest_AIJ\n";

 10: #include <petscmat.h>

 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:   PetscErrorCode      ierr;
 22:   PetscBool           equal;

 24:   PetscInitialize(&argc,&args,(char*)0,help);if (ierr) return ierr;
 25:   comm = PETSC_COMM_WORLD;
 26:   MPI_Comm_size(comm,&size);

 28:   /*
 29:      Assemble the matrix for the five point stencil, YET AGAIN
 30:   */
 31:   MatCreate(comm,&A1);
 32:   m=2,n=2;
 33:   MatSetSizes(A1,PETSC_DECIDE,PETSC_DECIDE,m*n,m*n);
 34:   MatSetFromOptions(A1);
 35:   MatSetUp(A1);
 36:   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; MatSetValues(A1,1,&ii,1,&J,&v,INSERT_VALUES);}
 40:     if (i<m-1) {J = ii + n; MatSetValues(A1,1,&ii,1,&J,&v,INSERT_VALUES);}
 41:     if (j>0)   {J = ii - 1; MatSetValues(A1,1,&ii,1,&J,&v,INSERT_VALUES);}
 42:     if (j<n-1) {J = ii + 1; MatSetValues(A1,1,&ii,1,&J,&v,INSERT_VALUES);}
 43:     v = 4.0; MatSetValues(A1,1,&ii,1,&ii,&v,INSERT_VALUES);
 44:   }
 45:   MatAssemblyBegin(A1,MAT_FINAL_ASSEMBLY);
 46:   MatAssemblyEnd(A1,MAT_FINAL_ASSEMBLY);
 47:   MatView(A1,PETSC_VIEWER_STDOUT_WORLD);

 49:   MatDuplicate(A1,MAT_COPY_VALUES,&A2);
 50:   MatDuplicate(A1,MAT_COPY_VALUES,&A3);
 51:   MatDuplicate(A1,MAT_COPY_VALUES,&A4);

 53:   /*create a nest matrix */
 54:   MatCreate(comm,&nest);
 55:   MatSetType(nest,MATNEST);
 56:   mata[0]=A1,mata[1]=A2,mata[2]=A3,mata[3]=A4;
 57:   MatNestSetSubMats(nest,2,NULL,2,NULL,mata);
 58:   MatSetUp(nest);
 59:   MatConvert(nest,MATAIJ,MAT_INITIAL_MATRIX,&aij);
 60:   MatView(aij,PETSC_VIEWER_STDOUT_WORLD);

 62:   /* create a dense matrix */
 63:   MatGetSize(nest,&M,NULL);
 64:   MatGetLocalSize(nest,&m,NULL);
 65:   MatCreateDense(comm,m,PETSC_DECIDE,M,K,NULL,&B);
 66:   MatSetRandom(B,PETSC_NULL);
 67:   MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);
 68:   MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);

 70:   /* C = nest*B_dense */
 71:   MatMatMult(nest,B,MAT_INITIAL_MATRIX,PETSC_DEFAULT,&C);
 72:   MatMatMult(nest,B,MAT_REUSE_MATRIX,PETSC_DEFAULT,&C);
 73:   MatMatMultEqual(nest,B,C,10,&equal);
 74:   if (!equal) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_PLIB,"Error in C != nest*B_dense");

 76:   /* Test B = nest*C, reuse C and B with MatProductCreateWithMat() */
 77:   /* C has been obtained from nest*B. Clear internal data structures related to factors to prevent circular references */
 78:   MatProductClear(C);
 79:   MatProductCreateWithMat(nest,C,NULL,B);
 80:   MatProductSetType(B,MATPRODUCT_AB);
 81:   MatProductSetFromOptions(B);
 82:   MatProductSymbolic(B);
 83:   MatProductNumeric(B);
 84:   MatMatMultEqual(nest,C,B,10,&equal);
 85:   if (!equal) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_PLIB,"Error in B != nest*C_dense");
 86:   MatConvert(nest,MATAIJ,MAT_INPLACE_MATRIX,&nest);
 87:   MatEqual(nest,aij,&equal);
 88:   if (!equal) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_PLIB,"Error in aij != nest");
 89:   MatDestroy(&nest);

 91:   if (size > 1) { /* Do not know why this test fails for size = 1 */
 92:     MatCreateTranspose(A1,&A5); /* A1 is symmetric */
 93:     mata[0] = A5;
 94:     MatCreate(comm,&nest);
 95:     MatSetType(nest,MATNEST);
 96:     MatNestSetSubMats(nest,2,NULL,2,NULL,mata);
 97:     MatSetUp(nest);
 98:     MatMatMult(nest,B,MAT_INITIAL_MATRIX,PETSC_DEFAULT,&C1);
 99:     MatMatMult(nest,B,MAT_REUSE_MATRIX,PETSC_DEFAULT,&C1);

101:     MatMatMultEqual(nest,B,C1,10,&equal);
102:     if (!equal) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_PLIB,"Error in C1 != C");
103:     MatDestroy(&C1);
104:     MatDestroy(&A5);
105:     MatDestroy(&nest);
106:   }

108:   MatDestroy(&C);
109:   MatDestroy(&B);
110:   MatDestroy(&aij);
111:   MatDestroy(&A1);
112:   MatDestroy(&A2);
113:   MatDestroy(&A3);
114:   MatDestroy(&A4);
115:   PetscFinalize();
116:   return ierr;
117: }

119: /*TEST

121:    test:
122:       nsize: 2

124:    test:
125:       suffix: 2

127: TEST*/