Line data    Source code

       1             : /*
       2             :    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
       3             :    SLEPc - Scalable Library for Eigenvalue Problem Computations
       4             :    Copyright (c) 2002-, Universitat Politecnica de Valencia, Spain
       5             : 
       6             :    This file is part of SLEPc.
       7             :    SLEPc is distributed under a 2-clause BSD license (see LICENSE).
       8             :    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
       9             : */
      10             : 
      11             : static char help[] = "Test GSVD with user-provided initial vectors.\n\n"
      12             :   "The command line options are:\n"
      13             :   "  -m <m>, where <m> = number of rows of A.\n"
      14             :   "  -n <n>, where <n> = number of columns of A.\n"
      15             :   "  -p <p>, where <p> = number of rows of B.\n\n";
      16             : 
      17             : #include <slepcsvd.h>
      18             : 
      19             : /*
      20             :    This example solves a GSVD problem for the bidiagonal matrices
      21             : 
      22             :               |  1  2                     |       |  2                        |
      23             :               |     1  2                  |       | -1  2                     |
      24             :               |        1  2               |       |    -1  2                  |
      25             :           A = |          .  .             |   B = |       .  .                |
      26             :               |             .  .          |       |          .  .             |
      27             :               |                1  2       |       |            -1  2          |
      28             :               |                   1  2    |       |               -1  2       |
      29             :  */
      30             : 
      31           7 : int main(int argc,char **argv)
      32             : {
      33           7 :   Mat            A,B;
      34           7 :   SVD            svd;
      35           7 :   Vec            v0,w0;           /* initial vectors */
      36           7 :   VecType        vtype;
      37           7 :   PetscInt       m=22,n=20,p=22,Istart,Iend,i,col[2];
      38           7 :   PetscScalar    valsa[] = { 1, 2 }, valsb[] = { -1, 2 };
      39             : 
      40           7 :   PetscFunctionBeginUser;
      41           7 :   PetscCall(SlepcInitialize(&argc,&argv,NULL,help));
      42           7 :   PetscCall(PetscOptionsGetInt(NULL,NULL,"-m",&m,NULL));
      43           7 :   PetscCall(PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL));
      44           7 :   PetscCall(PetscOptionsGetInt(NULL,NULL,"-p",&p,NULL));
      45           7 :   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"\nGeneralized singular value decomposition, (%" PetscInt_FMT "+%" PetscInt_FMT ")x%" PetscInt_FMT "\n\n",m,p,n));
      46             : 
      47             :   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      48             :                      Generate the matrices
      49             :      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
      50             : 
      51           7 :   PetscCall(MatCreate(PETSC_COMM_WORLD,&A));
      52           7 :   PetscCall(MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,m,n));
      53           7 :   PetscCall(MatSetFromOptions(A));
      54           7 :   PetscCall(MatGetOwnershipRange(A,&Istart,&Iend));
      55         161 :   for (i=Istart;i<Iend;i++) {
      56         154 :     col[0]=i; col[1]=i+1;
      57         154 :     if (i<n-1) PetscCall(MatSetValues(A,1,&i,2,col,valsa,INSERT_VALUES));
      58         154 :     else if (i==n-1) PetscCall(MatSetValue(A,i,col[0],valsa[0],INSERT_VALUES));
      59             :   }
      60           7 :   PetscCall(MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY));
      61           7 :   PetscCall(MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY));
      62             : 
      63           7 :   PetscCall(MatCreate(PETSC_COMM_WORLD,&B));
      64           7 :   PetscCall(MatSetSizes(B,PETSC_DECIDE,PETSC_DECIDE,m,n));
      65           7 :   PetscCall(MatSetFromOptions(B));
      66           7 :   PetscCall(MatGetOwnershipRange(B,&Istart,&Iend));
      67         161 :   for (i=Istart;i<Iend;i++) {
      68         154 :     col[0]=i-1; col[1]=i;
      69         154 :     if (i==0) PetscCall(MatSetValue(B,i,col[1],valsb[1],INSERT_VALUES));
      70         147 :     else if (i<n) PetscCall(MatSetValues(B,1,&i,2,col,valsb,INSERT_VALUES));
      71         154 :     else if (i==n) PetscCall(MatSetValue(B,i,col[0],valsb[0],INSERT_VALUES));
      72             :   }
      73           7 :   PetscCall(MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY));
      74           7 :   PetscCall(MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY));
      75             : 
      76             :   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      77             :          Create the singular value solver, set options and solve
      78             :      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
      79             : 
      80           7 :   PetscCall(SVDCreate(PETSC_COMM_WORLD,&svd));
      81           7 :   PetscCall(SVDSetOperators(svd,A,B));
      82           7 :   PetscCall(SVDSetFromOptions(svd));
      83             : 
      84             :   /*
      85             :      Set the initial vectors. This is optional, if not done the initial
      86             :      vectors are set to random values
      87             :   */
      88           7 :   PetscCall(MatCreateVecs(A,&v0,NULL));        /* right initial vector, length n */
      89           7 :   PetscCall(VecCreate(PETSC_COMM_WORLD,&w0));  /* left initial vector, length m+p */
      90           7 :   PetscCall(VecSetSizes(w0,PETSC_DECIDE,m+p));
      91           7 :   PetscCall(VecGetType(v0,&vtype));
      92           7 :   PetscCall(VecSetType(w0,vtype));
      93           7 :   PetscCall(VecSet(v0,1.0));
      94           7 :   PetscCall(VecSet(w0,1.0));
      95           7 :   PetscCall(SVDSetInitialSpaces(svd,1,&v0,1,&w0));
      96             : 
      97             :   /*
      98             :      Compute solution
      99             :   */
     100           7 :   PetscCall(SVDSolve(svd));
     101           7 :   PetscCall(SVDErrorView(svd,SVD_ERROR_NORM,NULL));
     102             : 
     103             :   /* Free work space */
     104           7 :   PetscCall(VecDestroy(&v0));
     105           7 :   PetscCall(VecDestroy(&w0));
     106           7 :   PetscCall(SVDDestroy(&svd));
     107           7 :   PetscCall(MatDestroy(&A));
     108           7 :   PetscCall(MatDestroy(&B));
     109           7 :   PetscCall(SlepcFinalize());
     110             :   return 0;
     111             : }
     112             : 
     113             : /*TEST
     114             : 
     115             :    testset:
     116             :       args: -svd_nsv 3
     117             :       requires: !single
     118             :       output_file: output/test18_1.out
     119             :       test:
     120             :          suffix: 1
     121             :          args: -svd_type {{lapack cross cyclic}}
     122             :       test:
     123             :          suffix: 1_trlanczos
     124             :          args: -svd_type trlanczos -svd_trlanczos_gbidiag {{single upper lower}}
     125             :          requires: !__float128
     126             : 
     127             :    test:
     128             :       suffix: 2
     129             :       args: -svd_nsv 3 -svd_type trlanczos -svd_monitor_conditioning
     130             :       requires: double
     131             : 
     132             : TEST*/