Actual source code: test6.c

slepc-3.7.2 2016-07-19
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  1: /*
  2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
  4:    Copyright (c) 2002-2016, Universitat Politecnica de Valencia, Spain

  6:    This file is part of SLEPc.

  8:    SLEPc is free software: you can redistribute it and/or modify it under  the
  9:    terms of version 3 of the GNU Lesser General Public License as published by
 10:    the Free Software Foundation.

 12:    SLEPc  is  distributed in the hope that it will be useful, but WITHOUT  ANY
 13:    WARRANTY;  without even the implied warranty of MERCHANTABILITY or  FITNESS
 14:    FOR  A  PARTICULAR PURPOSE. See the GNU Lesser General Public  License  for
 15:    more details.

 17:    You  should have received a copy of the GNU Lesser General  Public  License
 18:    along with SLEPc. If not, see <http://www.gnu.org/licenses/>.
 19:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 20: */

 22: static char help[] = "Test DSGHIEP with compact storage.\n\n";

 24: #include <slepcds.h>

 28: int main(int argc,char **argv)
 29: {
 31:   DS             ds;
 32:   SlepcSC        sc;
 33:   PetscReal      *T,*s,re,im;
 34:   PetscScalar    *eigr,*eigi;
 35:   PetscInt       i,n=10,l=2,k=5,ld;
 36:   PetscViewer    viewer;
 37:   PetscBool      verbose;

 39:   SlepcInitialize(&argc,&argv,(char*)0,help);
 40:   PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
 41:   PetscPrintf(PETSC_COMM_WORLD,"Solve a Dense System of type GHIEP with compact storage - dimension %D.\n",n);
 42:   PetscOptionsGetInt(NULL,NULL,"-l",&l,NULL);
 43:   PetscOptionsGetInt(NULL,NULL,"-k",&k,NULL);
 44:   if (l>n || k>n || l>k) SETERRQ(PETSC_COMM_WORLD,1,"Wrong value of dimensions");
 45:   PetscOptionsHasName(NULL,NULL,"-verbose",&verbose);

 47:   /* Create DS object */
 48:   DSCreate(PETSC_COMM_WORLD,&ds);
 49:   DSSetType(ds,DSGHIEP);
 50:   DSSetFromOptions(ds);
 51:   ld = n+2;  /* test leading dimension larger than n */
 52:   DSAllocate(ds,ld);
 53:   DSSetDimensions(ds,n,0,l,k);
 54:   DSSetCompact(ds,PETSC_TRUE);

 56:   /* Set up viewer */
 57:   PetscViewerASCIIGetStdout(PETSC_COMM_WORLD,&viewer);
 58:   PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_INFO_DETAIL);
 59:   DSView(ds,viewer);
 60:   PetscViewerPopFormat(viewer);
 61:   if (verbose) {
 62:     PetscViewerPushFormat(viewer,PETSC_VIEWER_ASCII_MATLAB);
 63:   }

 65:   /* Fill arrow-tridiagonal matrix */
 66:   DSGetArrayReal(ds,DS_MAT_T,&T);
 67:   DSGetArrayReal(ds,DS_MAT_D,&s);
 68:   for (i=0;i<n;i++) T[i] = (PetscReal)(i+1);
 69:   for (i=k;i<n-1;i++) T[i+ld] = 1.0;
 70:   for (i=l;i<k;i++) T[i+2*ld] = 1.0;
 71:   T[2*ld+l+1] = -7; T[ld+k+1] = -7;
 72:   /* Signature matrix */
 73:   for (i=0;i<n;i++) s[i] = 1.0;
 74:   s[l+1] = -1.0;
 75:   s[k+1] = -1.0;
 76:   DSRestoreArrayReal(ds,DS_MAT_T,&T);
 77:   DSRestoreArrayReal(ds,DS_MAT_D,&s);
 78:   if (l==0 && k==0) {
 79:     DSSetState(ds,DS_STATE_INTERMEDIATE);
 80:   } else {
 81:     DSSetState(ds,DS_STATE_RAW);
 82:   }
 83:   if (verbose) {
 84:     PetscPrintf(PETSC_COMM_WORLD,"Initial - - - - - - - - -\n");
 85:     DSView(ds,viewer);
 86:   }

 88:   /* Solve */
 89:   PetscCalloc2(n,&eigr,n,&eigi);
 90:   DSGetSlepcSC(ds,&sc);
 91:   sc->comparison    = SlepcCompareLargestMagnitude;
 92:   sc->comparisonctx = NULL;
 93:   sc->map           = NULL;
 94:   sc->mapobj        = NULL;
 95:   DSSolve(ds,eigr,eigi);
 96:   DSSort(ds,eigr,eigi,NULL,NULL,NULL);
 97:   if (verbose) {
 98:     PetscPrintf(PETSC_COMM_WORLD,"After solve - - - - - - - - -\n");
 99:     DSView(ds,viewer);
100:   }

102:   /* Print eigenvalues */
103:   PetscPrintf(PETSC_COMM_WORLD,"Computed eigenvalues =\n");
104:   for (i=0;i<n;i++) {
105: #if defined(PETSC_USE_COMPLEX)
106:     re = PetscRealPart(eigr[i]);
107:     im = PetscImaginaryPart(eigr[i]);
108: #else
109:     re = eigr[i];
110:     im = eigi[i];
111: #endif
112:     if (PetscAbs(im)<1e-10) {
113:       PetscViewerASCIIPrintf(viewer,"  %.5f\n",(double)re);
114:     } else {
115:       PetscViewerASCIIPrintf(viewer,"  %.5f%+.5fi\n",(double)re,(double)im);
116:     }
117:   }
118:   PetscFree2(eigr,eigi);
119:   DSDestroy(&ds);
120:   SlepcFinalize();
121:   return ierr;
122: }