Date: 2021-09-20T09:43:47+00:00

Actual source code: test3.c
slepc-3.15.2 2021-09-20
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      1: /*
      2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
      4:    Copyright (c) 2002-2021, 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[] = "Test ST with two matrices.\n\n";

     13: #include <slepcst.h>

     15: int main(int argc,char **argv)
     16: {
     17:   Mat            A,B,M,mat[2];
     18:   ST             st;
     19:   Vec            v,w;
     20:   STType         type;
     21:   PetscScalar    sigma,tau;
     22:   PetscInt       n=10,i,Istart,Iend;

     25:   SlepcInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr;
     26:   PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL);
     27:   PetscPrintf(PETSC_COMM_WORLD,"\n1-D Laplacian plus diagonal, n=%D\n\n",n);

     29:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     30:      Compute the operator matrix for the 1-D Laplacian
     31:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

     33:   MatCreate(PETSC_COMM_WORLD,&A);
     34:   MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,n,n);
     35:   MatSetFromOptions(A);
     36:   MatSetUp(A);

     38:   MatCreate(PETSC_COMM_WORLD,&B);
     39:   MatSetSizes(B,PETSC_DECIDE,PETSC_DECIDE,n,n);
     40:   MatSetFromOptions(B);
     41:   MatSetUp(B);

     43:   MatGetOwnershipRange(A,&Istart,&Iend);
     44:   for (i=Istart;i<Iend;i++) {
     45:     MatSetValue(A,i,i,2.0,INSERT_VALUES);
     46:     if (i>0) {
     47:       MatSetValue(A,i,i-1,-1.0,INSERT_VALUES);
     48:       MatSetValue(B,i,i,(PetscScalar)i,INSERT_VALUES);
     49:     } else {
     50:       MatSetValue(B,i,i,-1.0,INSERT_VALUES);
     51:     }
     52:     if (i<n-1) { MatSetValue(A,i,i+1,-1.0,INSERT_VALUES); }
     53:   }
     54:   MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
     55:   MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
     56:   MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);
     57:   MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);
     58:   MatCreateVecs(A,&v,&w);
     59:   VecSet(v,1.0);

     61:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     62:                 Create the spectral transformation object
     63:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

     65:   STCreate(PETSC_COMM_WORLD,&st);
     66:   mat[0] = A;
     67:   mat[1] = B;
     68:   STSetMatrices(st,2,mat);
     69:   STSetTransform(st,PETSC_TRUE);
     70:   STSetFromOptions(st);

     72:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     73:               Apply the transformed operator for several ST's
     74:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

     76:   /* shift, sigma=0.0 */
     77:   STSetUp(st);
     78:   STGetType(st,&type);
     79:   PetscPrintf(PETSC_COMM_WORLD,"ST type %s\n",type);
     80:   STApply(st,v,w);
     81:   VecView(w,NULL);

     83:   /* shift, sigma=0.1 */
     84:   sigma = 0.1;
     85:   STSetShift(st,sigma);
     86:   STGetShift(st,&sigma);
     87:   PetscPrintf(PETSC_COMM_WORLD,"With shift=%g\n",(double)PetscRealPart(sigma));
     88:   STApply(st,v,w);
     89:   VecView(w,NULL);

     91:   /* sinvert, sigma=0.1 */
     92:   STPostSolve(st);   /* undo changes if inplace */
     93:   STSetType(st,STSINVERT);
     94:   STGetType(st,&type);
     95:   PetscPrintf(PETSC_COMM_WORLD,"ST type %s\n",type);
     96:   STGetShift(st,&sigma);
     97:   PetscPrintf(PETSC_COMM_WORLD,"With shift=%g\n",(double)PetscRealPart(sigma));
     98:   STApply(st,v,w);
     99:   VecView(w,NULL);

    101:   /* sinvert, sigma=-0.5 */
    102:   sigma = -0.5;
    103:   STSetShift(st,sigma);
    104:   STGetShift(st,&sigma);
    105:   PetscPrintf(PETSC_COMM_WORLD,"With shift=%g\n",(double)PetscRealPart(sigma));
    106:   STApply(st,v,w);
    107:   VecView(w,NULL);

    109:   /* cayley, sigma=-0.5, tau=-0.5 (equal to sigma by default) */
    110:   STPostSolve(st);   /* undo changes if inplace */
    111:   STSetType(st,STCAYLEY);
    112:   STSetUp(st);
    113:   STGetType(st,&type);
    114:   PetscPrintf(PETSC_COMM_WORLD,"ST type %s\n",type);
    115:   STGetShift(st,&sigma);
    116:   STCayleyGetAntishift(st,&tau);
    117:   PetscPrintf(PETSC_COMM_WORLD,"With shift=%g, antishift=%g\n",(double)PetscRealPart(sigma),(double)PetscRealPart(tau));
    118:   STApply(st,v,w);
    119:   VecView(w,NULL);

    121:   /* cayley, sigma=1.1, tau=1.1 (still equal to sigma) */
    122:   sigma = 1.1;
    123:   STSetShift(st,sigma);
    124:   STGetShift(st,&sigma);
    125:   STCayleyGetAntishift(st,&tau);
    126:   PetscPrintf(PETSC_COMM_WORLD,"With shift=%g, antishift=%g\n",(double)PetscRealPart(sigma),(double)PetscRealPart(tau));
    127:   STApply(st,v,w);
    128:   VecView(w,NULL);

    130:   /* cayley, sigma=1.1, tau=-1.0 */
    131:   tau = -1.0;
    132:   STCayleySetAntishift(st,tau);
    133:   STGetShift(st,&sigma);
    134:   STCayleyGetAntishift(st,&tau);
    135:   PetscPrintf(PETSC_COMM_WORLD,"With shift=%g, antishift=%g\n",(double)PetscRealPart(sigma),(double)PetscRealPart(tau));
    136:   STApply(st,v,w);
    137:   VecView(w,NULL);

    139:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    140:                   Check inner product matrix in Cayley
    141:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
    142:   STGetBilinearForm(st,&M);
    143:   MatMult(M,v,w);
    144:   VecView(w,NULL);

    146:   STDestroy(&st);
    147:   MatDestroy(&A);
    148:   MatDestroy(&B);
    149:   MatDestroy(&M);
    150:   VecDestroy(&v);
    151:   VecDestroy(&w);
    152:   SlepcFinalize();
    153:   return ierr;
    154: }

    156: /*TEST

    158:    test:
    159:       suffix: 1
    160:       args: -st_matmode {{copy inplace shell}}
    161:       output_file: output/test3_1.out
    162:       requires: !single

    164: TEST*/