Date: 2026-03-31T13:23:38+00:00

Actual source code: test1.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 LME interface functions, based on ex32.c.\n\n"
     12:   "The command line options are:\n"
     13:   "  -n <n>, where <n> = number of grid subdivisions in x dimension.\n"
     14:   "  -m <m>, where <m> = number of grid subdivisions in y dimension.\n\n";

     16: #include <slepclme.h>

     18: int main(int argc,char **argv)
     19: {
     20:   Mat                  A,B,C,C1,D;
     21:   LME                  lme;
     22:   PetscReal            tol,errest,error;
     23:   PetscScalar          *u;
     24:   PetscInt             N,n=10,m,Istart,Iend,II,maxit,ncv,i,j;
     25:   PetscBool            flg,testprefix=PETSC_FALSE,viewmatrices=PETSC_FALSE;
     26:   const char           *prefix;
     27:   LMEType              type;
     28:   LMEProblemType       ptype;
     29:   PetscViewerAndFormat *vf;

     31:   PetscFunctionBeginUser;
     32:   PetscCall(SlepcInitialize(&argc,&argv,NULL,help));

     34:   PetscCall(PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL));
     35:   PetscCall(PetscOptionsGetInt(NULL,NULL,"-m",&m,&flg));
     36:   if (!flg) m=n;
     37:   N = n*m;
     38:   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"\nLyapunov equation, N=%" PetscInt_FMT " (%" PetscInt_FMT "x%" PetscInt_FMT " grid)\n\n",N,n,m));
     39:   PetscCall(PetscOptionsGetBool(NULL,NULL,"-test_prefix",&testprefix,NULL));
     40:   PetscCall(PetscOptionsGetBool(NULL,NULL,"-view_matrices",&viewmatrices,NULL));

     42:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     43:                        Create the 2-D Laplacian, A
     44:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

     46:   PetscCall(MatCreate(PETSC_COMM_WORLD,&A));
     47:   PetscCall(MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,N,N));
     48:   PetscCall(MatSetFromOptions(A));
     49:   PetscCall(MatGetOwnershipRange(A,&Istart,&Iend));
     50:   for (II=Istart;II<Iend;II++) {
     51:     i = II/n; j = II-i*n;
     52:     if (i>0) PetscCall(MatSetValue(A,II,II-n,1.0,INSERT_VALUES));
     53:     if (i<m-1) PetscCall(MatSetValue(A,II,II+n,1.0,INSERT_VALUES));
     54:     if (j>0) PetscCall(MatSetValue(A,II,II-1,1.0,INSERT_VALUES));
     55:     if (j<n-1) PetscCall(MatSetValue(A,II,II+1,1.0,INSERT_VALUES));
     56:     PetscCall(MatSetValue(A,II,II,-4.0,INSERT_VALUES));
     57:   }
     58:   PetscCall(MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY));
     59:   PetscCall(MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY));

     61:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     62:        Create a low-rank Mat to store the right-hand side C = C1*C1'
     63:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

     65:   PetscCall(MatCreate(PETSC_COMM_WORLD,&C1));
     66:   PetscCall(MatSetSizes(C1,PETSC_DECIDE,PETSC_DECIDE,N,2));
     67:   PetscCall(MatSetType(C1,MATDENSE));
     68:   PetscCall(MatGetOwnershipRange(C1,&Istart,&Iend));
     69:   PetscCall(MatDenseGetArray(C1,&u));
     70:   for (i=Istart;i<Iend;i++) {
     71:     if (i<N/2) u[i-Istart] = 1.0;
     72:     if (i==0) u[i+Iend-2*Istart] = -2.0;
     73:     if (i==1) u[i+Iend-2*Istart] = -1.0;
     74:     if (i==2) u[i+Iend-2*Istart] = -1.0;
     75:   }
     76:   PetscCall(MatDenseRestoreArray(C1,&u));
     77:   PetscCall(MatAssemblyBegin(C1,MAT_FINAL_ASSEMBLY));
     78:   PetscCall(MatAssemblyEnd(C1,MAT_FINAL_ASSEMBLY));
     79:   PetscCall(MatCreateLRC(NULL,C1,NULL,NULL,&C));
     80:   PetscCall(MatDestroy(&C1));

     82:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     83:                 Create the solver and set various options
     84:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
     85:   PetscCall(LMECreate(PETSC_COMM_WORLD,&lme));
     86:   PetscCall(LMESetProblemType(lme,LME_SYLVESTER));
     87:   PetscCall(LMEGetProblemType(lme,&ptype));
     88:   PetscCall(PetscPrintf(PETSC_COMM_WORLD," Equation type set to %d\n",ptype));
     89:   PetscCall(LMESetProblemType(lme,LME_LYAPUNOV));
     90:   PetscCall(LMEGetProblemType(lme,&ptype));
     91:   PetscCall(PetscPrintf(PETSC_COMM_WORLD," Equation type changed to %d\n",ptype));
     92:   PetscCall(LMESetCoefficients(lme,A,NULL,NULL,NULL));
     93:   PetscCall(LMESetRHS(lme,C));

     95:   /* test prefix usage */
     96:   if (testprefix) {
     97:     PetscCall(LMESetOptionsPrefix(lme,"check_"));
     98:     PetscCall(LMEAppendOptionsPrefix(lme,"myprefix_"));
     99:     PetscCall(LMEGetOptionsPrefix(lme,&prefix));
    100:     PetscCall(PetscPrintf(PETSC_COMM_WORLD," LME prefix is currently: %s\n",prefix));
    101:   }

    103:   /* test some interface functions */
    104:   PetscCall(LMEGetCoefficients(lme,&B,NULL,NULL,NULL));
    105:   if (viewmatrices) PetscCall(MatView(B,PETSC_VIEWER_STDOUT_WORLD));
    106:   PetscCall(LMEGetRHS(lme,&D));
    107:   if (viewmatrices) PetscCall(MatView(D,PETSC_VIEWER_STDOUT_WORLD));
    108:   PetscCall(LMESetTolerances(lme,PETSC_CURRENT,100));
    109:   PetscCall(LMESetDimensions(lme,21));
    110:   PetscCall(LMESetErrorIfNotConverged(lme,PETSC_TRUE));
    111:   /* test monitors */
    112:   PetscCall(PetscViewerAndFormatCreate(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_DEFAULT,&vf));
    113:   PetscCall(LMEMonitorSet(lme,(PetscErrorCode (*)(LME,PetscInt,PetscReal,void*))LMEMonitorDefault,vf,(PetscCtxDestroyFn*)PetscViewerAndFormatDestroy));
    114:   /* PetscCall(LMEMonitorCancel(lme)); */
    115:   PetscCall(LMESetFromOptions(lme));

    117:   PetscCall(LMEGetType(lme,&type));
    118:   PetscCall(PetscPrintf(PETSC_COMM_WORLD," Solver being used: %s\n",type));

    120:   /* query properties and print them */
    121:   PetscCall(LMEGetTolerances(lme,&tol,&maxit));
    122:   PetscCall(PetscPrintf(PETSC_COMM_WORLD," Tolerance: %g, max iterations: %" PetscInt_FMT "\n",(double)tol,maxit));
    123:   PetscCall(LMEGetDimensions(lme,&ncv));
    124:   PetscCall(PetscPrintf(PETSC_COMM_WORLD," Subspace dimension: %" PetscInt_FMT "\n",ncv));
    125:   PetscCall(LMEGetErrorIfNotConverged(lme,&flg));
    126:   if (flg) PetscCall(PetscPrintf(PETSC_COMM_WORLD," Erroring out if convergence fails\n"));

    128:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    129:                 Solve the matrix equation and compute residual error
    130:      - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

    132:   PetscCall(LMESolve(lme));
    133:   PetscCall(LMEGetErrorEstimate(lme,&errest));
    134:   PetscCall(PetscPrintf(PETSC_COMM_WORLD," Error estimate reported by the solver: %.4g\n",(double)errest));
    135:   PetscCall(LMEComputeError(lme,&error));
    136:   PetscCall(PetscPrintf(PETSC_COMM_WORLD," Computed residual norm: %.4g\n\n",(double)error));

    138:   /*
    139:      Free work space
    140:   */
    141:   PetscCall(LMEDestroy(&lme));
    142:   PetscCall(MatDestroy(&A));
    143:   PetscCall(MatDestroy(&C));
    144:   PetscCall(SlepcFinalize());
    145:   return 0;
    146: }

    148: /*TEST

    150:    test:
    151:       suffix: 1
    152:       args: -lme_monitor_cancel -lme_converged_reason -lme_view -view_matrices -log_exclude lme,bv
    153:       requires: double
    154:       filter: sed -e "s/4.0[0-9]*e-10/4.03e-10/"

    156:    test:
    157:       suffix: 2
    158:       args: -test_prefix -check_myprefix_lme_monitor
    159:       requires: double
    160:       filter: sed -e "s/estimate [0-9]\.[0-9]*e[+-]\([0-9]*\)/estimate (removed)/g" | sed -e "s/4.0[0-9]*e-10/4.03e-10/"

    162:    test:
    163:       suffix: 3
    164:       args: -lme_monitor_cancel -info -lme_monitor draw::draw_lg -draw_virtual
    165:       requires: x double
    166:       filter: sed -e "s/equation = [0-9]\.[0-9]*e[+-]\([0-9]*\)/equation = (removed)/g" | sed -e "s/4.0[0-9]*e-10/4.03e-10/" | grep -v Comm | grep -v machine | grep -v PetscGetHostName | grep -v OpenMP | grep -v Colormap | grep -v "Rank of the Cholesky factor" | grep -v "potrf failed" | grep -v "querying" | grep -v FPTrap | grep -v Device | grep -v SetNumThread

    168: TEST*/