Actual source code: snestest.c

  1: #define PETSCSNES_DLL

 3:  #include private/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:   PetscReal      nrm,gnorm;
 23:   SNES_Test      *neP = (SNES_Test*)snes->data;


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

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

 38:   for (i=0; i<3; i++) {
 39:     if (i == 1) {VecSet(x,-1.0);}
 40:     else if (i == 2) {VecSet(x,1.0);}
 41: 
 42:     /* compute both versions of Jacobian */
 43:     SNESComputeJacobian(snes,x,&A,&A,&flg);
 44:     if (!i) {MatConvert(A,MATSAME,MAT_INITIAL_MATRIX,&B);}
 45:     SNESDefaultComputeJacobian(snes,x,&B,&B,&flg,snes->funP);
 46:     if (neP->complete_print) {
 47:       MPI_Comm    comm;
 48:       PetscViewer viewer;
 49:       PetscPrintf(((PetscObject)snes)->comm,"Finite difference Jacobian\n");
 50:       PetscObjectGetComm((PetscObject)B,&comm);
 51:       PetscViewerASCIIGetStdout(comm,&viewer);
 52:       MatView(B,viewer);
 53:     }
 54:     /* compare */
 55:     MatAXPY(B,-1.0,A,DIFFERENT_NONZERO_PATTERN);
 56:     MatNorm(B,NORM_FROBENIUS,&nrm);
 57:     MatNorm(A,NORM_FROBENIUS,&gnorm);
 58:     if (neP->complete_print) {
 59:       MPI_Comm    comm;
 60:       PetscViewer viewer;
 61:       PetscPrintf(((PetscObject)snes)->comm,"Hand-coded Jacobian\n");
 62:       PetscObjectGetComm((PetscObject)B,&comm);
 63:       PetscViewerASCIIGetStdout(comm,&viewer);
 64:       MatView(A,viewer);
 65:     }
 66:     if (!gnorm) gnorm = 1; /* just in case */
 67:     PetscPrintf(((PetscObject)snes)->comm,"Norm of matrix ratio %G difference %G\n",nrm/gnorm,nrm);
 68:   }
 69:   MatDestroy(B);
 70:   /*
 71:          Return error code cause Jacobian not good
 72:   */
 73:   PetscFunctionReturn(PETSC_ERR_ARG_WRONGSTATE);
 74: }
 75: /* ------------------------------------------------------------ */
 78: PetscErrorCode SNESDestroy_Test(SNES snes)
 79: {
 82:   PetscFree(snes->data);
 83:   return(0);
 84: }

 88: static PetscErrorCode SNESSetFromOptions_Test(SNES snes)
 89: {
 90:   SNES_Test      *ls = (SNES_Test *)snes->data;


 95:   PetscOptionsHead("Hand-coded Jacobian tester options");
 96:     PetscOptionsName("-snes_test_display","Display difference between approximate and handcoded Jacobian","None",&ls->complete_print);
 97:   PetscOptionsTail();
 98:   return(0);
 99: }

101: /* ------------------------------------------------------------ */
102: /*MC
103:       SNESTEST - Test hand-coded Jacobian against finite difference Jacobian

105:    Options Database:
106: .    -snes_test_display  Display difference between approximate and hand-coded Jacobian

108:    Level: intermediate

110: .seealso:  SNESCreate(), SNES, SNESSetType(), SNESLS, SNESTR

112: M*/
116: PetscErrorCode  SNESCreate_Test(SNES  snes)
117: {
118:   SNES_Test      *neP;

122:   snes->ops->setup             = 0;
123:   snes->ops->solve             = SNESSolve_Test;
124:   snes->ops->destroy             = SNESDestroy_Test;
125:   snes->ops->setfromoptions  = SNESSetFromOptions_Test;
126:   snes->ops->view            = 0;

128:   ierr                        = PetscNewLog(snes,SNES_Test,&neP);
129:   snes->data            = (void*)neP;
130:   neP->complete_print   = PETSC_FALSE;
131:   return(0);
132: }