Actual source code: ex48.c

slepc-3.16.0 2021-09-30
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  1: /*
  2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
  4:    Copyright (c) 2002-2021, Universitat Politecnica de Valencia, Spain

  6:    This file is part of SLEPc.
  7:    SLEPc is distributed under a 2-clause BSD license (see LICENSE).
  8:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  9: */

 11: static char help[] = "Solves a GSVD problem with matrices loaded from a file.\n"
 12:   "The command line options are:\n"
 13:   "  -f1 <filename>, PETSc binary file containing matix A.\n"
 14:   "  -f2 <filename>, PETSc binary file containing matix B (optional).\n\n";

 16: #include <slepcsvd.h>

 18: int main(int argc,char **argv)
 19: {
 20:   Mat            A,B;             /* matrices */
 21:   SVD            svd;             /* singular value problem solver context */
 22:   PetscInt       i,m,n,Istart,Iend,col[2];
 23:   PetscScalar    vals[] = { -1, 1 };
 24:   char           filename[PETSC_MAX_PATH_LEN];
 25:   PetscViewer    viewer;
 26:   PetscBool      flg,terse;

 29:   SlepcInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr;

 31:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 32:         Load matrices that define the generalized singular value problem
 33:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 35:   PetscPrintf(PETSC_COMM_WORLD,"\nGeneralized singular value problem stored in file.\n\n");
 36:   PetscOptionsGetString(NULL,NULL,"-f1",filename,sizeof(filename),&flg);
 37:   if (!flg) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_USER_INPUT,"Must indicate a file name for matrix A with the -f1 option");

 39: #if defined(PETSC_USE_COMPLEX)
 40:   PetscPrintf(PETSC_COMM_WORLD," Reading COMPLEX matrix from a binary file...\n");
 41: #else
 42:   PetscPrintf(PETSC_COMM_WORLD," Reading REAL matrix from a binary file...\n");
 43: #endif
 44:   PetscViewerBinaryOpen(PETSC_COMM_WORLD,filename,FILE_MODE_READ,&viewer);
 45:   MatCreate(PETSC_COMM_WORLD,&A);
 46:   MatSetFromOptions(A);
 47:   MatLoad(A,viewer);
 48:   PetscViewerDestroy(&viewer);

 50:   MatGetSize(A,&m,&n);

 52:   PetscOptionsGetString(NULL,NULL,"-f2",filename,sizeof(filename),&flg);
 53:   if (flg) {
 54:     PetscViewerBinaryOpen(PETSC_COMM_WORLD,filename,FILE_MODE_READ,&viewer);
 55:     MatCreate(PETSC_COMM_WORLD,&B);
 56:     MatSetFromOptions(B);
 57:     MatLoad(B,viewer);
 58:     PetscViewerDestroy(&viewer);
 59:   } else {
 60:     PetscPrintf(PETSC_COMM_WORLD," Matrix B was not provided, setting B=bidiag(1,-1)\n\n");
 61:     MatCreate(PETSC_COMM_WORLD,&B);
 62:     MatSetSizes(B,PETSC_DECIDE,PETSC_DECIDE,n+1,n);
 63:     MatSetFromOptions(B);
 64:     MatSetUp(B);
 65:     MatGetOwnershipRange(B,&Istart,&Iend);
 66:     for (i=Istart;i<Iend;i++) {
 67:       col[0]=i-1; col[1]=i;
 68:       if (i==0) {
 69:         MatSetValue(B,i,col[1],vals[1],INSERT_VALUES);
 70:       } else if (i<n) {
 71:         MatSetValues(B,1,&i,2,col,vals,INSERT_VALUES);
 72:       } else if (i==n) {
 73:         MatSetValue(B,i,col[0],vals[0],INSERT_VALUES);
 74:       }
 75:     }
 76:     MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);
 77:     MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);
 78:   }

 80:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 81:            Create the singular value solver and set various options
 82:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 84:   /*
 85:      Create singular value solver context
 86:   */
 87:   SVDCreate(PETSC_COMM_WORLD,&svd);

 89:   /*
 90:      Set operators of GSVD problem
 91:   */
 92:   SVDSetOperators(svd,A,B);
 93:   SVDSetProblemType(svd,SVD_GENERALIZED);

 95:   /*
 96:      Set solver parameters at runtime
 97:   */
 98:   SVDSetFromOptions(svd);

100:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
101:                       Solve the problem and print solution
102:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

104:   SVDSolve(svd);

106:   /* show detailed info unless -terse option is given by user */
107:   PetscOptionsHasName(NULL,NULL,"-terse",&terse);
108:   if (terse) {
109:     SVDErrorView(svd,SVD_ERROR_RELATIVE,NULL);
110:   } else {
111:     PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_INFO_DETAIL);
112:     SVDConvergedReasonView(svd,PETSC_VIEWER_STDOUT_WORLD);
113:     SVDErrorView(svd,SVD_ERROR_RELATIVE,PETSC_VIEWER_STDOUT_WORLD);
114:     PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD);
115:   }
116:   SVDDestroy(&svd);
117:   MatDestroy(&A);
118:   MatDestroy(&B);
119:   SlepcFinalize();
120:   return ierr;
121: }
122: /*TEST

124:    testset:
125:       requires: double !complex !defined(PETSC_USE_64BIT_INDICES)
126:       args: -f1 ${SLEPC_DIR}/share/slepc/datafiles/matrices/bfw62a.petsc -f2 ${SLEPC_DIR}/share/slepc/datafiles/matrices/bfw62b.petsc -svd_nsv 3 -terse
127:       output_file: output/ex48_1.out
128:       test:
129:          suffix: 1
130:          args: -svd_type trlanczos -svd_trlanczos_explicitmatrix {{0 1}}
131:          TODO: does not work for largest singular values
132:       test:
133:          suffix: 1_spqr
134:          args: -svd_type trlanczos -svd_trlanczos_explicitmatrix -svd_trlanczos_pc_type qr
135:          requires: suitesparse
136:          TODO: does not work for largest singular values
137:       test:
138:          suffix: 1_cross
139:          args: -svd_type cross -svd_cross_explicitmatrix
140:       test:
141:          suffix: 1_cyclic
142:          args: -svd_type cyclic -svd_cyclic_explicitmatrix

144:    testset:
145:       requires: double complex datafilespath !defined(PETSC_USE_64BIT_INDICES)
146:       args: -f1 ${DATAFILESPATH}/matrices/complex/qc324.petsc -svd_nsv 3 -terse
147:       output_file: output/ex48_2.out
148:       test:
149:          suffix: 2
150:          args: -svd_type trlanczos -svd_tol 1e-10 -svd_trlanczos_explicitmatrix {{0 1}} -svd_trlanczos_ksp_rtol 1e-11
151:       test:
152:          suffix: 2_spqr
153:          args: -svd_type trlanczos -svd_tol 1e-10 -svd_trlanczos_explicitmatrix -svd_trlanczos_pc_type qr -svd_trlanczos_ksp_rtol 1e-11
154:          requires: suitesparse
155:       test:
156:          suffix: 2_cross
157:          args: -svd_type cross -svd_cross_explicitmatrix
158:       test:
159:          suffix: 2_cyclic
160:          args: -svd_type cyclic -svd_cyclic_explicitmatrix

162: TEST*/