Actual source code: snestest.c

  1: #define PETSCSNES_DLL

 3:  #include src/snes/snesimpl.h

  5: typedef struct {
  6:   PetscTruth complete_print;
  7: } SNES_Test;

  9: /*
 10:      SNESSolve_Test - Tests whether a hand computed Jacobian 
 11:      matches one compute via finite differences.
 12: */
 15: PetscErrorCode SNESSolve_Test(SNES snes)
 16: {
 17:   Mat            A = snes->jacobian,B;
 18:   Vec            x = snes->vec_sol;
 20:   PetscInt       i;
 21:   MatStructure   flg;
 22:   PetscScalar    mone = -1.0,one = 1.0;
 23:   PetscReal      nrm,gnorm;
 24:   SNES_Test      *neP = (SNES_Test*)snes->data;


 28:   if (A != snes->jacobian_pre) {
 29:     SETERRQ(PETSC_ERR_ARG_WRONG,"Cannot test with alternative preconditioner");
 30:   }

 32:   PetscPrintf(snes->comm,"Testing hand-coded Jacobian, if the ratio is\n");
 33:   PetscPrintf(snes->comm,"O(1.e-8), the hand-coded Jacobian is probably correct.\n");
 34:   if (!neP->complete_print) {
 35:     PetscPrintf(snes->comm,"Run with -snes_test_display to show difference\n");
 36:     PetscPrintf(snes->comm,"of hand-coded and finite difference Jacobian.\n");
 37:   }

 39:   for (i=0; i<3; i++) {
 40:     if (i == 1) {VecSet(x,mone);}
 41:     else if (i == 2) {VecSet(x,one);}
 42: 
 43:     /* compute both versions of Jacobian */
 44:     SNESComputeJacobian(snes,x,&A,&A,&flg);
 45:     if (!i) {MatConvert(A,MATSAME,MAT_INITIAL_MATRIX,&B);}
 46:     SNESDefaultComputeJacobian(snes,x,&B,&B,&flg,snes->funP);
 47:     if (neP->complete_print) {
 48:       MPI_Comm comm;
 49:       PetscPrintf(snes->comm,"Finite difference Jacobian\n");
 50:       PetscObjectGetComm((PetscObject)B,&comm);
 51:       MatView(B,PETSC_VIEWER_STDOUT_(comm));
 52:     }
 53:     /* compare */
 54:     MatAXPY(B,mone,A,DIFFERENT_NONZERO_PATTERN);
 55:     MatNorm(B,NORM_FROBENIUS,&nrm);
 56:     MatNorm(A,NORM_FROBENIUS,&gnorm);
 57:     if (neP->complete_print) {
 58:       MPI_Comm comm;
 59:       PetscPrintf(snes->comm,"Hand-coded Jacobian\n");
 60:       PetscObjectGetComm((PetscObject)B,&comm);
 61:       MatView(A,PETSC_VIEWER_STDOUT_(comm));
 62:     }
 63:     PetscPrintf(snes->comm,"Norm of matrix ratio %g difference %g\n",nrm/gnorm,nrm);
 64:   }
 65:   MatDestroy(B);
 66:   /*
 67:          Return error code cause Jacobian not good
 68:   */
 69:   PetscFunctionReturn(PETSC_ERR_ARG_WRONGSTATE);
 70: }
 71: /* ------------------------------------------------------------ */
 74: PetscErrorCode SNESDestroy_Test(SNES snes)
 75: {
 77:   return(0);
 78: }

 82: static PetscErrorCode SNESSetFromOptions_Test(SNES snes)
 83: {
 84:   SNES_Test      *ls = (SNES_Test *)snes->data;


 89:   PetscOptionsHead("Hand-coded Jacobian tester options");
 90:     PetscOptionsName("-snes_test_display","Display difference between approximate and handcoded Jacobian","None",&ls->complete_print);
 91:   PetscOptionsTail();
 92:   return(0);
 93: }

 95: /* ------------------------------------------------------------ */
 99: PetscErrorCode PETSCSNES_DLLEXPORT SNESCreate_Test(SNES  snes)
100: {
101:   SNES_Test      *neP;

105:   snes->setup                = 0;
106:   snes->solve                = SNESSolve_Test;
107:   snes->destroy                = SNESDestroy_Test;
108:   snes->converged        = SNESConverged_LS;
109:   snes->setfromoptions  = SNESSetFromOptions_Test;

111:   ierr                        = PetscNew(SNES_Test,&neP);
112:   PetscLogObjectMemory(snes,sizeof(SNES_Test));
113:   snes->data            = (void*)neP;
114:   neP->complete_print   = PETSC_FALSE;
115:   return(0);
116: }