Date: 2022-03-31T15:29:23+00:00

Actual source code: ex14.c
slepc-3.17.0 2022-03-31
Report Typos and Errors

      1: /*
      2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
      4:    Copyright (c) 2002-, 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 singular value problem with the matrix loaded from a file.\n"
     12:   "This example works for both real and complex numbers.\n\n"
     13:   "The command line options are:\n"
     14:   "  -file <filename>, where <filename> = matrix file in PETSc binary form.\n\n";

     16: #include <slepcsvd.h>

     18: int main(int argc,char **argv)
     19: {
     20:   Mat            A;               /* operator matrix */
     21:   SVD            svd;             /* singular value problem solver context */
     22:   SVDType        type;
     23:   PetscReal      tol;
     24:   PetscInt       nsv,maxit,its;
     25:   char           filename[PETSC_MAX_PATH_LEN];
     26:   PetscViewer    viewer;
     27:   PetscBool      flg,terse;

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

     31:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     32:         Load the operator matrix that defines the singular value problem
     33:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

     35:   PetscPrintf(PETSC_COMM_WORLD,"\nSingular value problem stored in file.\n\n");
     36:   PetscOptionsGetString(NULL,NULL,"-file",filename,sizeof(filename),&flg);

     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:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     51:                 Create the singular value solver and set various options
     52:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

     54:   /*
     55:      Create singular value solver context
     56:   */
     57:   SVDCreate(PETSC_COMM_WORLD,&svd);

     59:   /*
     60:      Set operator
     61:   */
     62:   SVDSetOperators(svd,A,NULL);

     64:   /*
     65:      Set solver parameters at runtime
     66:   */
     67:   SVDSetFromOptions(svd);

     69:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     70:                       Solve the singular value system
     71:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

     73:   SVDSolve(svd);
     74:   SVDGetIterationNumber(svd,&its);
     75:   PetscPrintf(PETSC_COMM_WORLD," Number of iterations of the method: %" PetscInt_FMT "\n",its);

     77:   /*
     78:      Optional: Get some information from the solver and display it
     79:   */
     80:   SVDGetType(svd,&type);
     81:   PetscPrintf(PETSC_COMM_WORLD," Solution method: %s\n\n",type);
     82:   SVDGetDimensions(svd,&nsv,NULL,NULL);
     83:   PetscPrintf(PETSC_COMM_WORLD," Number of requested singular values: %" PetscInt_FMT "\n",nsv);
     84:   SVDGetTolerances(svd,&tol,&maxit);
     85:   PetscPrintf(PETSC_COMM_WORLD," Stopping condition: tol=%.4g, maxit=%" PetscInt_FMT "\n",(double)tol,maxit);

     87:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     88:                     Display solution and clean up
     89:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

     91:   /* show detailed info unless -terse option is given by user */
     92:   PetscOptionsHasName(NULL,NULL,"-terse",&terse);
     93:   if (terse) SVDErrorView(svd,SVD_ERROR_RELATIVE,NULL);
     94:   else {
     95:     PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_INFO_DETAIL);
     96:     SVDConvergedReasonView(svd,PETSC_VIEWER_STDOUT_WORLD);
     97:     SVDErrorView(svd,SVD_ERROR_RELATIVE,PETSC_VIEWER_STDOUT_WORLD);
     98:     PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD);
     99:   }
    100:   SVDDestroy(&svd);
    101:   MatDestroy(&A);
    102:   SlepcFinalize();
    103:   return 0;
    104: }
    105: /*TEST

    107:    testset:
    108:       requires: double !complex !defined(PETSC_USE_64BIT_INDICES)
    109:       args: -file ${SLEPC_DIR}/share/slepc/datafiles/matrices/rdb200.petsc -terse
    110:       test:
    111:          suffix: 1
    112:          args: -svd_nsv 4 -svd_standard -svd_ncv 12 -svd_type {{trlanczos lanczos randomized cross}}
    113:          filter: grep -v method
    114:       test:
    115:          suffix: 1_scalapack
    116:          nsize: {{1 2 3}}
    117:          args: -svd_nsv 4 -svd_type scalapack
    118:          requires: scalapack
    119:       test:
    120:          suffix: 1_elemental
    121:          nsize: {{1 2 3}}
    122:          args: -svd_nsv 4 -svd_type elemental
    123:          requires: elemental
    124:       test:
    125:          suffix: 2
    126:          args: -svd_nsv 2 -svd_type cyclic -svd_cyclic_explicitmatrix -svd_cyclic_st_type sinvert -svd_cyclic_eps_target 12.0 -svd_cyclic_st_ksp_type preonly -svd_cyclic_st_pc_type lu -svd_view
    127:          filter: grep -v tolerance
    128:       test:
    129:          suffix: 2_cross
    130:          args: -svd_nsv 2 -svd_type cross -svd_cross_explicitmatrix -svd_cross_st_type sinvert -svd_cross_eps_target 100.0
    131:          filter: grep -v tolerance

    133:    testset:
    134:       requires: double complex datafilespath !defined(PETSC_USE_64BIT_INDICES)
    135:       args: -file ${DATAFILESPATH}/matrices/complex/qc324.petsc -terse
    136:       test:
    137:          suffix: 1_complex
    138:          args: -svd_nsv 4
    139:       test:
    140:          suffix: 1_complex_scalapack
    141:          nsize: {{1 2 3}}
    142:          args: -svd_nsv 4 -svd_type scalapack
    143:          requires: scalapack
    144:       test:
    145:          suffix: 1_complex_elemental
    146:          nsize: {{1 2 3}}
    147:          args: -svd_nsv 4 -svd_type elemental
    148:          requires: elemental
    149:       test:
    150:          suffix: 2_complex
    151:          args: -svd_nsv 2 -svd_type cyclic -svd_cyclic_explicitmatrix -svd_cyclic_st_type sinvert -svd_cyclic_eps_target 12.0 -svd_cyclic_st_ksp_type preonly -svd_cyclic_st_pc_type lu -svd_view
    152:          filter: grep -v tolerance

    154:    testset:
    155:       args: -svd_nsv 5 -svd_type randomized -svd_max_it 1 -svd_conv_maxit
    156:       test:
    157:          suffix: 3
    158:          args: -file ${SLEPC_DIR}/share/slepc/datafiles/matrices/rdb200.petsc
    159:          requires: double !complex !defined(PETSC_USE_64BIT_INDICES)
    160:       test:
    161:          suffix: 3_complex
    162:          args: -file ${DATAFILESPATH}/matrices/complex/qc324.petsc
    163:          requires: double complex datafilespath !defined(PETSC_USE_64BIT_INDICES)
    164:          filter: sed -e 's/[0-9][0-9]$//'

    166: TEST*/