Date: 2022-08-09T09:05:29+00:00

Actual source code: test2.c
slepc-3.17.2 2022-08-09
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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 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;
     22:   PetscInt       n=10,i,Istart,Iend;

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

     28:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     29:      Compute the operator matrix for the 1-D Laplacian
     30:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

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

     37:   MatGetOwnershipRange(A,&Istart,&Iend);
     38:   for (i=Istart;i<Iend;i++) {
     39:     if (i>0) MatSetValue(A,i,i-1,-1.0,INSERT_VALUES);
     40:     if (i<n-1) MatSetValue(A,i,i+1,-1.0,INSERT_VALUES);
     41:     MatSetValue(A,i,i,2.0,INSERT_VALUES);
     42:   }
     43:   MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
     44:   MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
     45:   MatCreateVecs(A,&v,&w);
     46:   VecSet(v,1.0);

     48:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     49:                 Create the spectral transformation object
     50:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

     52:   STCreate(PETSC_COMM_WORLD,&st);
     53:   mat[0] = A;
     54:   STSetMatrices(st,1,mat);
     55:   STSetTransform(st,PETSC_TRUE);
     56:   STSetFromOptions(st);

     58:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     59:               Apply the transformed operator for several ST's
     60:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

     62:   /* shift, sigma=0.0 */
     63:   STSetUp(st);
     64:   STGetType(st,&type);
     65:   PetscPrintf(PETSC_COMM_WORLD,"ST type %s\n",type);
     66:   STApply(st,v,w);
     67:   VecView(w,NULL);

     69:   /* shift, sigma=0.1 */
     70:   sigma = 0.1;
     71:   STSetShift(st,sigma);
     72:   STGetShift(st,&sigma);
     73:   PetscPrintf(PETSC_COMM_WORLD,"With shift=%g\n",(double)PetscRealPart(sigma));
     74:   STApply(st,v,w);
     75:   VecView(w,NULL);
     76:   STApplyTranspose(st,v,w);
     77:   VecView(w,NULL);

     79:   /* sinvert, sigma=0.1 */
     80:   STPostSolve(st);   /* undo changes if inplace */
     81:   STSetType(st,STSINVERT);
     82:   STGetType(st,&type);
     83:   PetscPrintf(PETSC_COMM_WORLD,"ST type %s\n",type);
     84:   STGetShift(st,&sigma);
     85:   PetscPrintf(PETSC_COMM_WORLD,"With shift=%g\n",(double)PetscRealPart(sigma));
     86:   STApply(st,v,w);
     87:   VecView(w,NULL);

     89:   /* sinvert, sigma=-0.5 */
     90:   sigma = -0.5;
     91:   STSetShift(st,sigma);
     92:   STGetShift(st,&sigma);
     93:   PetscPrintf(PETSC_COMM_WORLD,"With shift=%g\n",(double)PetscRealPart(sigma));
     94:   STApply(st,v,w);
     95:   VecView(w,NULL);

     97:   /* cayley, sigma=-0.5, tau=-0.5 (equal to sigma by default) */
     98:   STPostSolve(st);   /* undo changes if inplace */
     99:   STSetType(st,STCAYLEY);
    100:   STSetUp(st);
    101:   STGetType(st,&type);
    102:   PetscPrintf(PETSC_COMM_WORLD,"ST type %s\n",type);
    103:   STGetShift(st,&sigma);
    104:   STCayleyGetAntishift(st,&tau);
    105:   PetscPrintf(PETSC_COMM_WORLD,"With shift=%g, antishift=%g\n",(double)PetscRealPart(sigma),(double)PetscRealPart(tau));
    106:   STApply(st,v,w);
    107:   VecView(w,NULL);

    109:   /* cayley, sigma=1.1, tau=1.1 (still equal to sigma) */
    110:   sigma = 1.1;
    111:   STSetShift(st,sigma);
    112:   STGetShift(st,&sigma);
    113:   STCayleyGetAntishift(st,&tau);
    114:   PetscPrintf(PETSC_COMM_WORLD,"With shift=%g, antishift=%g\n",(double)PetscRealPart(sigma),(double)PetscRealPart(tau));
    115:   STApply(st,v,w);
    116:   VecView(w,NULL);

    118:   /* cayley, sigma=1.1, tau=-1.0 */
    119:   tau = -1.0;
    120:   STCayleySetAntishift(st,tau);
    121:   STGetShift(st,&sigma);
    122:   STCayleyGetAntishift(st,&tau);
    123:   PetscPrintf(PETSC_COMM_WORLD,"With shift=%g, antishift=%g\n",(double)PetscRealPart(sigma),(double)PetscRealPart(tau));
    124:   STApply(st,v,w);
    125:   VecView(w,NULL);

    127:   /* check inner product matrix in Cayley */
    128:   STGetBilinearForm(st,&B);
    129:   MatMult(B,v,w);
    130:   VecView(w,NULL);

    132:   /* check again sinvert, sigma=0.1 */
    133:   STPostSolve(st);   /* undo changes if inplace */
    134:   STSetType(st,STSINVERT);
    135:   STGetType(st,&type);
    136:   PetscPrintf(PETSC_COMM_WORLD,"ST type %s\n",type);
    137:   sigma = 0.1;
    138:   STSetShift(st,sigma);
    139:   STGetShift(st,&sigma);
    140:   PetscPrintf(PETSC_COMM_WORLD,"With shift=%g\n",(double)PetscRealPart(sigma));
    141:   STApply(st,v,w);
    142:   VecView(w,NULL);

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

    153: /*TEST

    155:    test:
    156:       suffix: 1
    157:       args: -st_matmode {{copy inplace shell}}
    158:       output_file: output/test2_1.out
    159:       requires: !single

    161: TEST*/