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[] = "Tests user interface for TRLANCZOS with GSVD.\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"
 16:   "  -s <s>, where <s> = scale parameter.\n\n";

 18: #include <slepcsvd.h>

 20: int main(int argc,char **argv)
 21: {
 22:   Mat                 A,B;
 23:   SVD                 svd;
 24:   KSP                 ksp;
 25:   PC                  pc;
 26:   PetscInt            m=15,n=20,p=21,i,j,d,Istart,Iend;
 27:   PetscReal           keep,scale=1.0;
 28:   PetscBool           flg,lock,oneside;
 29:   SVDTRLanczosGBidiag bidiag;

 31:   PetscFunctionBeginUser;
 32:   PetscCall(SlepcInitialize(&argc,&argv,(char*)0,help));
 33:   PetscCall(PetscOptionsGetInt(NULL,NULL,"-m",&m,NULL));
 34:   PetscCall(PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL));
 35:   PetscCall(PetscOptionsGetInt(NULL,NULL,"-p",&p,NULL));
 36:   PetscCall(PetscOptionsGetReal(NULL,NULL,"-s",&scale,NULL));
 37:   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"\nGeneralized singular value decomposition, (%" PetscInt_FMT "+%" PetscInt_FMT ")x%" PetscInt_FMT "\n\n",m,p,n));

 39:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 40:                      Generate the matrices
 41:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 43:   PetscCall(MatCreate(PETSC_COMM_WORLD,&A));
 44:   PetscCall(MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,m,n));
 45:   PetscCall(MatSetFromOptions(A));

 47:   PetscCall(MatGetOwnershipRange(A,&Istart,&Iend));
 48:   for (i=Istart;i<Iend;i++) {
 49:     if (i>0 && i-1<n) PetscCall(MatSetValue(A,i,i-1,-1.0,INSERT_VALUES));
 50:     if (i+1<n) PetscCall(MatSetValue(A,i,i+1,-1.0,INSERT_VALUES));
 51:     if (i<n) PetscCall(MatSetValue(A,i,i,2.0,INSERT_VALUES));
 52:     if (i>n) PetscCall(MatSetValue(A,i,n-1,1.0,INSERT_VALUES));
 53:   }
 54:   PetscCall(MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY));
 55:   PetscCall(MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY));

 57:   PetscCall(MatCreate(PETSC_COMM_WORLD,&B));
 58:   PetscCall(MatSetSizes(B,PETSC_DECIDE,PETSC_DECIDE,p,n));
 59:   PetscCall(MatSetFromOptions(B));

 61:   PetscCall(MatGetOwnershipRange(B,&Istart,&Iend));
 62:   d = PetscMax(0,n-p);
 63:   for (i=Istart;i<Iend;i++) {
 64:     for (j=0;j<=PetscMin(i,n-1);j++) PetscCall(MatSetValue(B,i,j+d,1.0,INSERT_VALUES));
 65:   }
 66:   PetscCall(MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY));
 67:   PetscCall(MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY));

 69:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 70:          Create the singular value solver, set options and solve
 71:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

 73:   PetscCall(SVDCreate(PETSC_COMM_WORLD,&svd));
 74:   PetscCall(SVDSetOperators(svd,A,B));
 75:   PetscCall(SVDSetProblemType(svd,SVD_GENERALIZED));
 76:   PetscCall(SVDSetDimensions(svd,4,PETSC_DEFAULT,PETSC_DEFAULT));
 77:   PetscCall(SVDSetConvergenceTest(svd,SVD_CONV_NORM));

 79:   PetscCall(SVDSetType(svd,SVDTRLANCZOS));
 80:   PetscCall(SVDTRLanczosSetGBidiag(svd,SVD_TRLANCZOS_GBIDIAG_UPPER));
 81:   PetscCall(SVDTRLanczosSetScale(svd,scale));

 83:   /* create a standalone KSP with appropriate settings */
 84:   PetscCall(KSPCreate(PETSC_COMM_WORLD,&ksp));
 85:   PetscCall(KSPSetType(ksp,KSPLSQR));
 86:   PetscCall(KSPGetPC(ksp,&pc));
 87:   PetscCall(PCSetType(pc,PCNONE));
 88:   PetscCall(KSPSetTolerances(ksp,PETSC_SMALL,PETSC_DEFAULT,PETSC_DEFAULT,PETSC_DEFAULT));
 89:   PetscCall(KSPSetFromOptions(ksp));
 90:   PetscCall(SVDTRLanczosSetKSP(svd,ksp));
 91:   PetscCall(SVDTRLanczosSetRestart(svd,0.4));
 92:   PetscCall(SVDTRLanczosSetLocking(svd,PETSC_TRUE));

 94:   PetscCall(SVDSetFromOptions(svd));

 96:   PetscCall(PetscObjectTypeCompare((PetscObject)svd,SVDTRLANCZOS,&flg));
 97:   if (flg) {
 98:     PetscCall(SVDTRLanczosGetGBidiag(svd,&bidiag));
 99:     PetscCall(PetscPrintf(PETSC_COMM_WORLD,"TRLANCZOS: using %s bidiagonalization\n",SVDTRLanczosGBidiags[bidiag]));
100:     PetscCall(SVDTRLanczosGetRestart(svd,&keep));
101:     PetscCall(SVDTRLanczosGetLocking(svd,&lock));
102:     PetscCall(PetscPrintf(PETSC_COMM_WORLD,"TRLANCZOS: restarting parameter %.2f %s\n",(double)keep,lock?"(locking)":""));
103:     PetscCall(SVDTRLanczosGetScale(svd,&scale));
104:     PetscCall(PetscPrintf(PETSC_COMM_WORLD,"TRLANCZOS: scale parameter %g\n",(double)scale));
105:     PetscCall(SVDTRLanczosGetOneSide(svd,&oneside));
106:     if (oneside) PetscCall(PetscPrintf(PETSC_COMM_WORLD,"TRLANCZOS: using one-sided orthogonalization\n"));
107:   }

109:   PetscCall(SVDSolve(svd));
110:   PetscCall(SVDErrorView(svd,SVD_ERROR_NORM,NULL));

112:   /* Free work space */
113:   PetscCall(SVDDestroy(&svd));
114:   PetscCall(KSPDestroy(&ksp));
115:   PetscCall(MatDestroy(&A));
116:   PetscCall(MatDestroy(&B));
117:   PetscCall(SlepcFinalize());
118:   return 0;
119: }

121: /*TEST

123:    test:
124:       suffix: 1
125:       args: -svd_trlanczos_gbidiag {{single upper lower}}
126:       filter: grep -v "TRLANCZOS: using"
127:       requires: !single

129:    test:
130:       suffix: 2
131:       args: -m 6 -n 12 -p 12 -svd_trlanczos_restart .7
132:       requires: !single

134:    test:
135:       suffix: 3
136:       args: -s 8 -svd_trlanczos_gbidiag lower
137:       requires: !single

139:    test:
140:       suffix: 4
141:       args: -s -5 -svd_trlanczos_gbidiag lower
142:       requires: !single

144: TEST*/