Date: 2026-01-20T11:35:29+00:00

Actual source code: test2.c

      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 one matrix.\n\n";

     13: #include <slepcst.h>

     15: int main(int argc,char **argv)
     16: {
     17:   Mat            A,B,mat[1];
     18:   ST             st;
     19:   Vec            v,w;
     20:   STType         type;
     21:   PetscScalar    sigma,tau,val;
     22:   PetscInt       n=10,i,Istart,Iend;
     23:   PetscBool      test_compl=PETSC_FALSE;

     25:   PetscFunctionBeginUser;
     26:   PetscCall(SlepcInitialize(&argc,&argv,NULL,help));
     27:   PetscCall(PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL));
     28:   PetscCall(PetscOptionsGetBool(NULL,NULL,"-complex",&test_compl,NULL));
     29:   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"\n1-D Laplacian, n=%" PetscInt_FMT "\n\n",n));

     31:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     32:      Compute the operator matrix for the 1-D Laplacian
     33:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

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

     39:   PetscCall(MatGetOwnershipRange(A,&Istart,&Iend));
     40: #if defined(PETSC_USE_COMPLEX)
     41:   val = test_compl? PetscCMPLX(-1.0,0.4): -1.0;
     42: #else
     43:   val = -1.0;
     44: #endif
     45:   for (i=Istart;i<Iend;i++) {
     46:     if (i>0) PetscCall(MatSetValue(A,i,i-1,val,INSERT_VALUES));
     47:     if (i<n-1) PetscCall(MatSetValue(A,i,i+1,PetscConj(val),INSERT_VALUES));
     48:     PetscCall(MatSetValue(A,i,i,2.0,INSERT_VALUES));
     49:   }
     50:   PetscCall(MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY));
     51:   PetscCall(MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY));
     52:   PetscCall(MatCreateVecs(A,&v,&w));
     53: #if defined(PETSC_USE_COMPLEX)
     54:   val = test_compl? PetscCMPLX(1.0,-0.01): 1.0;
     55: #else
     56:   val = 1.0;
     57: #endif
     58:   PetscCall(VecSet(v,val));

     60:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     61:                 Create the spectral transformation object
     62:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

     64:   PetscCall(STCreate(PETSC_COMM_WORLD,&st));
     65:   mat[0] = A;
     66:   PetscCall(STSetMatrices(st,1,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));
     88:   PetscCall(STApplyTranspose(st,v,w));
     89:   PetscCall(VecView(w,NULL));
     90:   if (test_compl) {
     91:     PetscCall(STApplyHermitianTranspose(st,v,w));
     92:     PetscCall(VecView(w,NULL));
     93:   }

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

    105:   /* sinvert, sigma=-0.5 */
    106:   sigma = -0.5;
    107:   PetscCall(STSetShift(st,sigma));
    108:   PetscCall(STGetShift(st,&sigma));
    109:   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"With shift=%g\n",(double)PetscRealPart(sigma)));
    110:   PetscCall(STApply(st,v,w));
    111:   PetscCall(VecView(w,NULL));
    112:   if (test_compl) {
    113:     PetscCall(STApplyHermitianTranspose(st,v,w));
    114:     PetscCall(VecView(w,NULL));
    115:   }

    117:   /* cayley, sigma=-0.5, tau=-0.5 (equal to sigma by default) */
    118:   PetscCall(STPostSolve(st));   /* undo changes if inplace */
    119:   PetscCall(STSetType(st,STCAYLEY));
    120:   PetscCall(STSetUp(st));
    121:   PetscCall(STGetType(st,&type));
    122:   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"ST type %s\n",type));
    123:   PetscCall(STGetShift(st,&sigma));
    124:   PetscCall(STCayleyGetAntishift(st,&tau));
    125:   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"With shift=%g, antishift=%g\n",(double)PetscRealPart(sigma),(double)PetscRealPart(tau)));
    126:   PetscCall(STApply(st,v,w));
    127:   PetscCall(VecView(w,NULL));

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

    138:   /* cayley, sigma=1.1, tau=-1.0 */
    139:   tau = -1.0;
    140:   PetscCall(STCayleySetAntishift(st,tau));
    141:   PetscCall(STGetShift(st,&sigma));
    142:   PetscCall(STCayleyGetAntishift(st,&tau));
    143:   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"With shift=%g, antishift=%g\n",(double)PetscRealPart(sigma),(double)PetscRealPart(tau)));
    144:   PetscCall(STApply(st,v,w));
    145:   PetscCall(VecView(w,NULL));

    147:   /* check inner product matrix in Cayley */
    148:   PetscCall(STGetBilinearForm(st,&B));
    149:   PetscCall(MatMult(B,v,w));
    150:   PetscCall(VecView(w,NULL));

    152:   /* check again sinvert, sigma=0.1 */
    153:   PetscCall(STPostSolve(st));   /* undo changes if inplace */
    154:   PetscCall(STSetType(st,STSINVERT));
    155:   PetscCall(STGetType(st,&type));
    156:   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"ST type %s\n",type));
    157:   sigma = 0.1;
    158:   PetscCall(STSetShift(st,sigma));
    159:   PetscCall(STGetShift(st,&sigma));
    160:   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"With shift=%g\n",(double)PetscRealPart(sigma)));
    161:   PetscCall(STApply(st,v,w));
    162:   PetscCall(VecView(w,NULL));

    164:   PetscCall(STDestroy(&st));
    165:   PetscCall(MatDestroy(&A));
    166:   PetscCall(MatDestroy(&B));
    167:   PetscCall(VecDestroy(&v));
    168:   PetscCall(VecDestroy(&w));
    169:   PetscCall(SlepcFinalize());
    170:   return 0;
    171: }

    173: /*TEST

    175:    test:
    176:       suffix: 1
    177:       args: -st_matmode {{copy inplace shell}}
    178:       requires: !single

    180:    test:
    181:       suffix: 2
    182:       args: -complex -st_matmode {{copy inplace shell}}
    183:       requires: complex !single
    184:       filter: sed -e "s/3.46945e-18 - 8.67362e-18 i/0./"

    186: TEST*/