Date: 2023-11-27T17:19:52+00:00

Actual source code: test3.c
slepc-3.20.1 2023-11-27
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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[] = "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;

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

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

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

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

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

     59:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     60:                 Create the spectral transformation object
     61:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

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

     70:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     71:               Apply the transformed operator for several ST's
     72:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

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

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

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

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

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

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

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

    137:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    138:                   Check inner product matrix in Cayley
    139:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
    140:   PetscCall(STGetBilinearForm(st,&M));
    141:   PetscCall(MatMult(M,v,w));
    142:   PetscCall(VecView(w,NULL));

    144:   PetscCall(STDestroy(&st));
    145:   PetscCall(MatDestroy(&A));
    146:   PetscCall(MatDestroy(&B));
    147:   PetscCall(MatDestroy(&M));
    148:   PetscCall(VecDestroy(&v));
    149:   PetscCall(VecDestroy(&w));
    150:   PetscCall(SlepcFinalize());
    151:   return 0;
    152: }

    154: /*TEST

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

    162: TEST*/