63   subroutine FormInitialGuess(X, ierr)
67     PetscErrorCode ierr
71     ierr = 0
81     call VecGetArray(X, lx_v, ierr)
82     CHKERRQ(ierr)
86     call InitialGuessLocal(lx_v, ierr)
87     CHKERRQ(ierr)
91     call VecRestoreArray(X, lx_v, ierr)
92     CHKERRQ(ierr)
111   subroutine InitialGuessLocal(x, ierr)  argument
115     PetscErrorCode ierr
123     ierr = 0
158   subroutine FormFunctionLocal(info, x, f, da, ierr)  argument
166     PetscErrorCode ierr
204     call PetscLogFlops(11.0d0*ym*xm, ierr)
205     CHKERRQ(ierr)
245   subroutine FormJacobianLocal(info, x, A, jac, da, ierr)  argument
252     PetscErrorCode ierr
296           call MatSetValuesLocal(jac, i1, [row], i1, [col], [v], INSERT_VALUES, ierr)
297           CHKERRQ(ierr)
310           call MatSetValuesLocal(jac, i1, [row], i5, [col], [v], INSERT_VALUES, ierr)
311           CHKERRQ(ierr)
315     call MatAssemblyBegin(jac, MAT_FINAL_ASSEMBLY, ierr)
316     CHKERRQ(ierr)
317     call MatAssemblyEnd(jac, MAT_FINAL_ASSEMBLY, ierr)
318     CHKERRQ(ierr)
320       call MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY, ierr)
321       CHKERRQ(ierr)
322       call MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY, ierr)
323       CHKERRQ(ierr)
330   subroutine MySNESConverged(snes, it, xnorm, snorm, fnorm, reason, dummy, ierr)  argument
337     PetscErrorCode ierr
339     call SNESGetFunction(snes, f, PETSC_NULL_FUNCTION, dummy, ierr)
340     CHKERRQ(ierr)
341     call VecNorm(f, NORM_INFINITY, nrm, ierr)
342     CHKERRQ(ierr)
367   PetscErrorCode ierr
376   call PetscInitialize(ierr)
377   CHKERRA(ierr)
378   call MPI_Comm_size(PETSC_COMM_WORLD, size, ierr)
379   CHKERRMPIA(ierr)
380   call MPI_Comm_rank(PETSC_COMM_WORLD, rank, ierr)
381   CHKERRMPIA(ierr)
389 …etscOptionsGetReal(PETSC_NULL_OPTIONS, PETSC_NULL_CHARACTER, '-par', lambda, PETSC_NULL_BOOL, ierr)
390   CHKERRA(ierr)
394     ierr = PETSC_ERR_ARG_OUTOFRANGE
395     SETERRA(PETSC_COMM_WORLD, ierr, 'Lambda')
402   call SNESCreate(PETSC_COMM_WORLD, snes, ierr)
403   CHKERRA(ierr)
407 …ll PetscOptionsHasName(PETSC_NULL_OPTIONS, PETSC_NULL_CHARACTER, '-my_snes_convergence', flg, ierr)
408   CHKERRA(ierr)
410     call SNESSetConvergenceTest(snes, MySNESConverged, 0, PETSC_NULL_FUNCTION, ierr)
411     CHKERRA(ierr)
423                     i1, i1, PETSC_NULL_INTEGER_ARRAY, PETSC_NULL_INTEGER_ARRAY, da, ierr)
424   CHKERRA(ierr)
425   call DMSetFromOptions(da, ierr)
426   CHKERRA(ierr)
427   call DMSetUp(da, ierr)
428   CHKERRA(ierr)
433   call DMCreateGlobalVector(da, x, ierr)
434   CHKERRA(ierr)
435   call VecDuplicate(x, r, ierr)
436   CHKERRA(ierr)
442                    PETSC_NULL_DMBOUNDARYTYPE, PETSC_NULL_DMDASTENCILTYPE, ierr)
443   CHKERRA(ierr)
444   call DMDAGetCorners(da, xs, ys, PETSC_NULL_INTEGER, xm, ym, PETSC_NULL_INTEGER, ierr)
445   CHKERRA(ierr)
446   call DMDAGetGhostCorners(da, gxs, gys, PETSC_NULL_INTEGER, gxm, gym, PETSC_NULL_INTEGER, ierr)
447   CHKERRA(ierr)
464   call DMDASNESSetFunctionLocal(da, INSERT_VALUES, FormFunctionLocal, da, ierr)
465   CHKERRA(ierr)
466   call DMDASNESSetJacobianLocal(da, FormJacobianLocal, da, ierr)
467   CHKERRA(ierr)
468   call SNESSetDM(snes, da, ierr)
469   CHKERRA(ierr)
477   call SNESSetFromOptions(snes, ierr)
478   CHKERRA(ierr)
488   call FormInitialGuess(x, ierr)
489   CHKERRA(ierr)
490   call SNESSolve(snes, PETSC_NULL_VEC, x, ierr)
491   CHKERRA(ierr)
492   call SNESGetIterationNumber(snes, its, ierr)
493   CHKERRA(ierr)
504   call VecDestroy(x, ierr)
505   CHKERRA(ierr)
506   call VecDestroy(r, ierr)
507   CHKERRA(ierr)
508   call SNESDestroy(snes, ierr)
509   CHKERRA(ierr)
510   call DMDestroy(da, ierr)
511   CHKERRA(ierr)
512   call PetscFinalize(ierr)
513   CHKERRA(ierr)