Actual source code: test15.c

slepc-3.18.1 2022-11-02
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  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;

 32:   SlepcInitialize(&argc,&argv,(char*)0,help);
 33:   PetscOptionsGetInt(NULL,NULL,"-m",&m,NULL);
 34:   PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
 35:   PetscOptionsGetInt(NULL,NULL,"-p",&p,NULL);
 36:   PetscOptionsGetReal(NULL,NULL,"-s",&scale,NULL);
 37:   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:   MatCreate(PETSC_COMM_WORLD,&A);
 44:   MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,m,n);
 45:   MatSetFromOptions(A);
 46:   MatSetUp(A);

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

 58:   MatCreate(PETSC_COMM_WORLD,&B);
 59:   MatSetSizes(B,PETSC_DECIDE,PETSC_DECIDE,p,n);
 60:   MatSetFromOptions(B);
 61:   MatSetUp(B);

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

 71:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 72:          Create the singular value solver, set options and solve
 73:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

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

 81:   SVDSetType(svd,SVDTRLANCZOS);
 82:   SVDTRLanczosSetGBidiag(svd,SVD_TRLANCZOS_GBIDIAG_UPPER);
 83:   SVDTRLanczosSetScale(svd,scale);

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

 96:   SVDSetFromOptions(svd);

 98:   PetscObjectTypeCompare((PetscObject)svd,SVDTRLANCZOS,&flg);
 99:   if (flg) {
100:     SVDTRLanczosGetGBidiag(svd,&bidiag);
101:     PetscPrintf(PETSC_COMM_WORLD,"TRLANCZOS: using %s bidiagonalization\n",SVDTRLanczosGBidiags[bidiag]);
102:     SVDTRLanczosGetRestart(svd,&keep);
103:     SVDTRLanczosGetLocking(svd,&lock);
104:     PetscPrintf(PETSC_COMM_WORLD,"TRLANCZOS: restarting parameter %.2f %s\n",(double)keep,lock?"(locking)":"");
105:     SVDTRLanczosGetScale(svd,&scale);
106:     PetscPrintf(PETSC_COMM_WORLD,"TRLANCZOS: scale parameter %g\n",(double)scale);
107:     SVDTRLanczosGetOneSide(svd,&oneside);
108:     if (oneside) PetscPrintf(PETSC_COMM_WORLD,"TRLANCZOS: using one-sided orthogonalization\n");
109:   }

111:   SVDSolve(svd);
112:   SVDErrorView(svd,SVD_ERROR_NORM,NULL);

114:   /* Free work space */
115:   SVDDestroy(&svd);
116:   KSPDestroy(&ksp);
117:   MatDestroy(&A);
118:   MatDestroy(&B);
119:   SlepcFinalize();
120:   return 0;
121: }

123: /*TEST

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

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

136:    test:
137:       suffix: 3
138:       args: -s 8 -svd_trlanczos_gbidiag lower
139:       requires: !single

141:    test:
142:       suffix: 4
143:       args: -s -5 -svd_trlanczos_gbidiag lower
144:       requires: !single

146: TEST*/