xref: /petsc/include/petscsnes.h (revision a3afe2d1ed14aa25e6e8bcdd861505b3816b69e5)
1 /*
2     User interface for the nonlinear solvers package.
3 */
4 #if !defined(__PETSCSNES_H)
5 #define __PETSCSNES_H
6 #include <petscksp.h>
7 #include <petscdmtypes.h>
8 #include <petscdmdatypes.h>
9 
10 /*S
11      SNES - Abstract PETSc object that manages all nonlinear solves
12 
13    Level: beginner
14 
15   Concepts: nonlinear solvers
16 
17 .seealso:  SNESCreate(), SNESSetType(), SNESType, TS, KSP, KSP, PC, SNESDestroy()
18 S*/
19 typedef struct _p_SNES* SNES;
20 
21 /*J
22     SNESType - String with the name of a PETSc SNES method.
23 
24    Level: beginner
25 
26 .seealso: SNESSetType(), SNES, SNESCreate(), SNESDestroy(), SNESSetFromOptions()
27 J*/
28 typedef const char* SNESType;
29 #define SNESNEWTONLS     "newtonls"
30 #define SNESNEWTONTR     "newtontr"
31 #define SNESPYTHON       "python"
32 #define SNESTEST         "test"
33 #define SNESNRICHARDSON  "nrichardson"
34 #define SNESKSPONLY      "ksponly"
35 #define SNESVINEWTONRSLS "vinewtonrsls"
36 #define SNESVINEWTONSSLS "vinewtonssls"
37 #define SNESNGMRES       "ngmres"
38 #define SNESQN           "qn"
39 #define SNESSHELL        "shell"
40 #define SNESGS           "gs"
41 #define SNESNCG          "ncg"
42 #define SNESFAS          "fas"
43 #define SNESMS           "ms"
44 #define SNESNASM         "nasm"
45 #define SNESANDERSON     "anderson"
46 #define SNESASPIN        "aspin"
47 
48 /* Logging support */
49 PETSC_EXTERN PetscClassId SNES_CLASSID;
50 PETSC_EXTERN PetscClassId DMSNES_CLASSID;
51 
52 PETSC_EXTERN PetscErrorCode SNESInitializePackage(void);
53 
54 PETSC_EXTERN PetscErrorCode SNESCreate(MPI_Comm,SNES*);
55 PETSC_EXTERN PetscErrorCode SNESReset(SNES);
56 PETSC_EXTERN PetscErrorCode SNESDestroy(SNES*);
57 PETSC_EXTERN PetscErrorCode SNESSetType(SNES,SNESType);
58 PETSC_EXTERN PetscErrorCode SNESMonitor(SNES,PetscInt,PetscReal);
59 PETSC_EXTERN PetscErrorCode SNESMonitorSet(SNES,PetscErrorCode(*)(SNES,PetscInt,PetscReal,void*),void *,PetscErrorCode (*)(void**));
60 PETSC_EXTERN PetscErrorCode SNESMonitorCancel(SNES);
61 PETSC_EXTERN PetscErrorCode SNESSetConvergenceHistory(SNES,PetscReal[],PetscInt[],PetscInt,PetscBool );
62 PETSC_EXTERN PetscErrorCode SNESGetConvergenceHistory(SNES,PetscReal*[],PetscInt *[],PetscInt *);
63 PETSC_EXTERN PetscErrorCode SNESSetUp(SNES);
64 PETSC_EXTERN PetscErrorCode SNESSolve(SNES,Vec,Vec);
65 PETSC_EXTERN PetscErrorCode SNESSetErrorIfNotConverged(SNES,PetscBool );
66 PETSC_EXTERN PetscErrorCode SNESGetErrorIfNotConverged(SNES,PetscBool  *);
67 
68 PETSC_EXTERN PetscErrorCode SNESSetWorkVecs(SNES,PetscInt);
69 
70 PETSC_EXTERN PetscErrorCode SNESAddOptionsChecker(PetscErrorCode (*)(SNES));
71 
72 PETSC_EXTERN PetscErrorCode SNESSetUpdate(SNES, PetscErrorCode (*)(SNES, PetscInt));
73 
74 PETSC_EXTERN PetscErrorCode SNESRegisterAll(void);
75 
76 PETSC_EXTERN PetscErrorCode SNESRegister(const char[],PetscErrorCode (*)(SNES));
77 
78 PETSC_EXTERN PetscErrorCode SNESGetKSP(SNES,KSP*);
79 PETSC_EXTERN PetscErrorCode SNESSetKSP(SNES,KSP);
80 PETSC_EXTERN PetscErrorCode SNESGetSolution(SNES,Vec*);
81 PETSC_EXTERN PetscErrorCode SNESGetSolutionUpdate(SNES,Vec*);
82 PETSC_EXTERN PetscErrorCode SNESGetRhs(SNES,Vec*);
83 PETSC_EXTERN PetscErrorCode SNESView(SNES,PetscViewer);
84 PETSC_EXTERN PetscErrorCode SNESLoad(SNES,PetscViewer);
85 
86 #define SNES_FILE_CLASSID 1211224
87 
88 PETSC_EXTERN PetscErrorCode SNESSetOptionsPrefix(SNES,const char[]);
89 PETSC_EXTERN PetscErrorCode SNESAppendOptionsPrefix(SNES,const char[]);
90 PETSC_EXTERN PetscErrorCode SNESGetOptionsPrefix(SNES,const char*[]);
91 PETSC_EXTERN PetscErrorCode SNESSetFromOptions(SNES);
92 
93 PETSC_EXTERN PetscErrorCode MatCreateSNESMF(SNES,Mat*);
94 PETSC_EXTERN PetscErrorCode MatMFFDComputeJacobian(SNES,Vec,Mat*,Mat*,MatStructure*,void*);
95 
96 PETSC_EXTERN PetscErrorCode MatDAADSetSNES(Mat,SNES);
97 
98 PETSC_EXTERN PetscErrorCode SNESGetType(SNES,SNESType*);
99 PETSC_EXTERN PetscErrorCode SNESMonitorDefault(SNES,PetscInt,PetscReal,void *);
100 PETSC_EXTERN PetscErrorCode SNESMonitorRange(SNES,PetscInt,PetscReal,void *);
101 PETSC_EXTERN PetscErrorCode SNESMonitorRatio(SNES,PetscInt,PetscReal,void *);
102 PETSC_EXTERN PetscErrorCode SNESMonitorSetRatio(SNES,PetscViewer);
103 PETSC_EXTERN PetscErrorCode SNESMonitorSolution(SNES,PetscInt,PetscReal,void *);
104 PETSC_EXTERN PetscErrorCode SNESMonitorResidual(SNES,PetscInt,PetscReal,void *);
105 PETSC_EXTERN PetscErrorCode SNESMonitorSolutionUpdate(SNES,PetscInt,PetscReal,void *);
106 PETSC_EXTERN PetscErrorCode SNESMonitorDefaultShort(SNES,PetscInt,PetscReal,void *);
107 PETSC_EXTERN PetscErrorCode SNESMonitorJacUpdateSpectrum(SNES,PetscInt,PetscReal,void *);
108 PETSC_EXTERN PetscErrorCode SNESSetTolerances(SNES,PetscReal,PetscReal,PetscReal,PetscInt,PetscInt);
109 PETSC_EXTERN PetscErrorCode SNESGetTolerances(SNES,PetscReal*,PetscReal*,PetscReal*,PetscInt*,PetscInt*);
110 PETSC_EXTERN PetscErrorCode SNESSetTrustRegionTolerance(SNES,PetscReal);
111 PETSC_EXTERN PetscErrorCode SNESGetFunctionNorm(SNES,PetscReal*);
112 PETSC_EXTERN PetscErrorCode SNESSetFunctionNorm(SNES,PetscReal);
113 PETSC_EXTERN PetscErrorCode SNESGetIterationNumber(SNES,PetscInt*);
114 PETSC_EXTERN PetscErrorCode SNESSetIterationNumber(SNES,PetscInt);
115 
116 PETSC_EXTERN PetscErrorCode SNESGetNonlinearStepFailures(SNES,PetscInt*);
117 PETSC_EXTERN PetscErrorCode SNESSetMaxNonlinearStepFailures(SNES,PetscInt);
118 PETSC_EXTERN PetscErrorCode SNESGetMaxNonlinearStepFailures(SNES,PetscInt*);
119 PETSC_EXTERN PetscErrorCode SNESGetNumberFunctionEvals(SNES,PetscInt*);
120 
121 PETSC_EXTERN PetscErrorCode SNESSetLagPreconditioner(SNES,PetscInt);
122 PETSC_EXTERN PetscErrorCode SNESGetLagPreconditioner(SNES,PetscInt*);
123 PETSC_EXTERN PetscErrorCode SNESSetLagJacobian(SNES,PetscInt);
124 PETSC_EXTERN PetscErrorCode SNESGetLagJacobian(SNES,PetscInt*);
125 PETSC_EXTERN PetscErrorCode SNESSetGridSequence(SNES,PetscInt);
126 
127 PETSC_EXTERN PetscErrorCode SNESGetLinearSolveIterations(SNES,PetscInt*);
128 PETSC_EXTERN PetscErrorCode SNESGetLinearSolveFailures(SNES,PetscInt*);
129 PETSC_EXTERN PetscErrorCode SNESSetMaxLinearSolveFailures(SNES,PetscInt);
130 PETSC_EXTERN PetscErrorCode SNESGetMaxLinearSolveFailures(SNES,PetscInt*);
131 
132 PETSC_EXTERN PetscErrorCode SNESKSPSetUseEW(SNES,PetscBool );
133 PETSC_EXTERN PetscErrorCode SNESKSPGetUseEW(SNES,PetscBool *);
134 PETSC_EXTERN PetscErrorCode SNESKSPSetParametersEW(SNES,PetscInt,PetscReal,PetscReal,PetscReal,PetscReal,PetscReal,PetscReal);
135 PETSC_EXTERN PetscErrorCode SNESKSPGetParametersEW(SNES,PetscInt*,PetscReal*,PetscReal*,PetscReal*,PetscReal*,PetscReal*,PetscReal*);
136 
137 #include <petscdrawtypes.h>
138 PETSC_EXTERN PetscErrorCode SNESMonitorLGCreate(const char[],const char[],int,int,int,int,PetscDrawLG*);
139 PETSC_EXTERN PetscErrorCode SNESMonitorLGResidualNorm(SNES,PetscInt,PetscReal,void*);
140 PETSC_EXTERN PetscErrorCode SNESMonitorLGDestroy(PetscDrawLG*);
141 PETSC_EXTERN PetscErrorCode SNESMonitorLGRange(SNES,PetscInt,PetscReal,void*);
142 
143 PETSC_EXTERN PetscErrorCode SNESSetApplicationContext(SNES,void *);
144 PETSC_EXTERN PetscErrorCode SNESGetApplicationContext(SNES,void *);
145 PETSC_EXTERN PetscErrorCode SNESSetComputeApplicationContext(SNES,PetscErrorCode (*)(SNES,void**),PetscErrorCode (*)(void**));
146 
147 PETSC_EXTERN PetscErrorCode SNESPythonSetType(SNES,const char[]);
148 
149 PETSC_EXTERN PetscErrorCode SNESSetFunctionDomainError(SNES);
150 PETSC_EXTERN PetscErrorCode SNESGetFunctionDomainError(SNES, PetscBool *);
151 
152 /*E
153     SNESConvergedReason - reason a SNES method was said to
154          have converged or diverged
155 
156    Level: beginner
157 
158    The two most common reasons for divergence are
159 $   1) an incorrectly coded or computed Jacobian or
160 $   2) failure or lack of convergence in the linear system (in this case we recommend
161 $      testing with -pc_type lu to eliminate the linear solver as the cause of the problem).
162 
163    Diverged Reasons:
164 .    SNES_DIVERGED_LOCAL_MIN - this can only occur when using the line-search variant of SNES.
165        The line search wants to minimize Q(alpha) = 1/2 || F(x + alpha s) ||^2_2  this occurs
166        at Q'(alpha) = s^T F'(x+alpha s)^T F(x+alpha s) = 0. If s is the Newton direction - F'(x)^(-1)F(x) then
167        you get Q'(alpha) = -F(x)^T F'(x)^(-1)^T F'(x+alpha s)F(x+alpha s); when alpha = 0
168        Q'(0) = - ||F(x)||^2_2 which is always NEGATIVE if F'(x) is invertible. This means the Newton
169        direction is a descent direction and the line search should succeed if alpha is small enough.
170 
171        If F'(x) is NOT invertible AND F'(x)^T F(x) = 0 then Q'(0) = 0 and the Newton direction
172        is NOT a descent direction so the line search will fail. All one can do at this point
173        is change the initial guess and try again.
174 
175        An alternative explanation: Newton's method can be regarded as replacing the function with
176        its linear approximation and minimizing the 2-norm of that. That is F(x+s) approx F(x) + F'(x)s
177        so we minimize || F(x) + F'(x) s ||^2_2; do this using Least Squares. If F'(x) is invertible then
178        s = - F'(x)^(-1)F(x) otherwise F'(x)^T F'(x) s = -F'(x)^T F(x). If F'(x)^T F(x) is NOT zero then there
179        exists a nontrival (that is F'(x)s != 0) solution to the equation and this direction is
180        s = - [F'(x)^T F'(x)]^(-1) F'(x)^T F(x) so Q'(0) = - F(x)^T F'(x) [F'(x)^T F'(x)]^(-T) F'(x)^T F(x)
181        = - (F'(x)^T F(x)) [F'(x)^T F'(x)]^(-T) (F'(x)^T F(x)). Since we are assuming (F'(x)^T F(x)) != 0
182        and F'(x)^T F'(x) has no negative eigenvalues Q'(0) < 0 so s is a descent direction and the line
183        search should succeed for small enough alpha.
184 
185        Note that this RARELY happens in practice. Far more likely the linear system is not being solved
186        (well enough?) or the Jacobian is wrong.
187 
188    SNES_DIVERGED_MAX_IT means that the solver reached the maximum number of iterations without satisfying any
189    convergence criteria. SNES_CONVERGED_ITS means that SNESSkipConverged() was chosen as the convergence test;
190    thus the usual convergence criteria have not been checked and may or may not be satisfied.
191 
192    Developer Notes: this must match finclude/petscsnes.h
193 
194        The string versions of these are in SNESConvergedReason, if you change any value here you must
195      also adjust that array.
196 
197    Each reason has its own manual page.
198 
199 .seealso: SNESSolve(), SNESGetConvergedReason(), KSPConvergedReason, SNESSetConvergenceTest()
200 E*/
201 typedef enum {/* converged */
202               SNES_CONVERGED_FNORM_ABS         =  2, /* ||F|| < atol */
203               SNES_CONVERGED_FNORM_RELATIVE    =  3, /* ||F|| < rtol*||F_initial|| */
204               SNES_CONVERGED_SNORM_RELATIVE    =  4, /* Newton computed step size small; || delta x || < stol || x ||*/
205               SNES_CONVERGED_ITS               =  5, /* maximum iterations reached */
206               SNES_CONVERGED_TR_DELTA          =  7,
207               /* diverged */
208               SNES_DIVERGED_FUNCTION_DOMAIN     = -1, /* the new x location passed the function is not in the domain of F */
209               SNES_DIVERGED_FUNCTION_COUNT      = -2,
210               SNES_DIVERGED_LINEAR_SOLVE        = -3, /* the linear solve failed */
211               SNES_DIVERGED_FNORM_NAN           = -4,
212               SNES_DIVERGED_MAX_IT              = -5,
213               SNES_DIVERGED_LINE_SEARCH         = -6, /* the line search failed */
214               SNES_DIVERGED_INNER               = -7, /* inner solve failed */
215               SNES_DIVERGED_LOCAL_MIN           = -8, /* || J^T b || is small, implies converged to local minimum of F() */
216               SNES_CONVERGED_ITERATING          =  0} SNESConvergedReason;
217 PETSC_EXTERN const char *const*SNESConvergedReasons;
218 
219 /*MC
220      SNES_CONVERGED_FNORM_ABS - 2-norm(F) <= abstol
221 
222    Level: beginner
223 
224 .seealso:  SNESSolve(), SNESGetConvergedReason(), SNESConvergedReason, SNESSetTolerances()
225 
226 M*/
227 
228 /*MC
229      SNES_CONVERGED_FNORM_RELATIVE - 2-norm(F) <= rtol*2-norm(F(x_0)) where x_0 is the initial guess
230 
231    Level: beginner
232 
233 .seealso:  SNESSolve(), SNESGetConvergedReason(), SNESConvergedReason, SNESSetTolerances()
234 
235 M*/
236 
237 /*MC
238      SNES_CONVERGED_SNORM_RELATIVE - The 2-norm of the last step <= stol * 2-norm(x) where x is the current
239           solution and stol is the 4th argument to SNESSetTolerances()
240 
241      Options Database Keys:
242       -snes_stol <stol> - the step tolerance
243 
244    Level: beginner
245 
246 .seealso:  SNESSolve(), SNESGetConvergedReason(), SNESConvergedReason, SNESSetTolerances()
247 
248 M*/
249 
250 /*MC
251      SNES_DIVERGED_FUNCTION_COUNT - The user provided function has been called more times then the final
252          argument to SNESSetTolerances()
253 
254    Level: beginner
255 
256 .seealso:  SNESSolve(), SNESGetConvergedReason(), SNESConvergedReason, SNESSetTolerances()
257 
258 M*/
259 
260 /*MC
261      SNES_DIVERGED_FNORM_NAN - the 2-norm of the current function evaluation is not-a-number (NaN), this
262       is usually caused by a division of 0 by 0.
263 
264    Level: beginner
265 
266 .seealso:  SNESSolve(), SNESGetConvergedReason(), SNESConvergedReason, SNESSetTolerances()
267 
268 M*/
269 
270 /*MC
271      SNES_DIVERGED_MAX_IT - SNESSolve() has reached the maximum number of iterations requested
272 
273    Level: beginner
274 
275 .seealso:  SNESSolve(), SNESGetConvergedReason(), SNESConvergedReason, SNESSetTolerances()
276 
277 M*/
278 
279 /*MC
280      SNES_DIVERGED_LINE_SEARCH - The line search has failed. This only occurs for a SNES solvers that use a line search
281 
282    Level: beginner
283 
284 .seealso:  SNESSolve(), SNESGetConvergedReason(), SNESConvergedReason, SNESSetTolerances(), SNESLineSearch
285 
286 M*/
287 
288 /*MC
289      SNES_DIVERGED_LOCAL_MIN - the algorithm seems to have stagnated at a local minimum that is not zero.
290         See the manual page for SNESConvergedReason for more details
291 
292    Level: beginner
293 
294 .seealso:  SNESSolve(), SNESGetConvergedReason(), SNESConvergedReason, SNESSetTolerances()
295 
296 M*/
297 
298 /*MC
299      SNES_CONERGED_ITERATING - this only occurs if SNESGetConvergedReason() is called during the SNESSolve()
300 
301    Level: beginner
302 
303 .seealso:  SNESSolve(), SNESGetConvergedReason(), SNESConvergedReason, SNESSetTolerances()
304 
305 M*/
306 
307 PETSC_EXTERN PetscErrorCode SNESSetConvergenceTest(SNES,PetscErrorCode (*)(SNES,PetscInt,PetscReal,PetscReal,PetscReal,SNESConvergedReason*,void*),void*,PetscErrorCode (*)(void*));
308 PETSC_EXTERN PetscErrorCode SNESConvergedDefault(SNES,PetscInt,PetscReal,PetscReal,PetscReal,SNESConvergedReason*,void*);
309 PETSC_EXTERN PetscErrorCode SNESSkipConverged(SNES,PetscInt,PetscReal,PetscReal,PetscReal,SNESConvergedReason*,void*);
310 PETSC_EXTERN PetscErrorCode SNESGetConvergedReason(SNES,SNESConvergedReason*);
311 
312 PETSC_EXTERN PetscErrorCode SNESDMMeshComputeFunction(SNES,Vec,Vec,void*);
313 PETSC_EXTERN PetscErrorCode SNESDMMeshComputeJacobian(SNES,Vec,Mat*,Mat*,MatStructure*,void*);
314 
315 /* --------- Solving systems of nonlinear equations --------------- */
316 PETSC_EXTERN PetscErrorCode SNESSetFunction(SNES,Vec,PetscErrorCode (*SNESFunction)(SNES,Vec,Vec,void*),void*);
317 PETSC_EXTERN PetscErrorCode SNESGetFunction(SNES,Vec*,PetscErrorCode (**SNESFunction)(SNES,Vec,Vec,void*),void**);
318 PETSC_EXTERN PetscErrorCode SNESComputeFunction(SNES,Vec,Vec);
319 PETSC_EXTERN PetscErrorCode SNESSetJacobian(SNES,Mat,Mat,PetscErrorCode (*SNESJacobianFunction)(SNES,Vec,Mat*,Mat*,MatStructure*,void*),void*);
320 PETSC_EXTERN PetscErrorCode SNESGetJacobian(SNES,Mat*,Mat*,PetscErrorCode (**SNESJacobianFunction)(SNES,Vec,Mat*,Mat*,MatStructure*,void*),void**);
321 PETSC_EXTERN PetscErrorCode SNESObjectiveComputeFunctionDefaultFD(SNES,Vec,Vec,void*);
322 PETSC_EXTERN PetscErrorCode SNESComputeJacobianDefault(SNES,Vec,Mat*,Mat*,MatStructure*,void*);
323 PETSC_EXTERN PetscErrorCode SNESComputeJacobianDefaultColor(SNES,Vec,Mat*,Mat*,MatStructure*,void*);
324 PETSC_EXTERN PetscErrorCode SNESSetComputeInitialGuess(SNES,PetscErrorCode (*)(SNES,Vec,void*),void*);
325 PETSC_EXTERN PetscErrorCode SNESSetPicard(SNES,Vec,PetscErrorCode (*SNESFunction)(SNES,Vec,Vec,void*),Mat,Mat,PetscErrorCode (*SNESJacobianFunction)(SNES,Vec,Mat*,Mat*,MatStructure*,void*),void*);
326 PETSC_EXTERN PetscErrorCode SNESGetPicard(SNES,Vec*,PetscErrorCode (**SNESFunction)(SNES,Vec,Vec,void*),Mat*,Mat*,PetscErrorCode (**SNESJacobianFunction)(SNES,Vec,Mat*,Mat*,MatStructure*,void*),void**);
327 PETSC_EXTERN PetscErrorCode SNESSetInitialFunction(SNES,Vec);
328 PETSC_EXTERN PetscErrorCode SNESSetInitialFunctionNorm(SNES,PetscReal);
329 
330 PETSC_EXTERN PetscErrorCode SNESSetObjective(SNES,PetscErrorCode (*SNESObjectiveFunction)(SNES,Vec,PetscReal *,void*),void*);
331 PETSC_EXTERN PetscErrorCode SNESGetObjective(SNES,PetscErrorCode (**SNESObjectiveFunction)(SNES,Vec,PetscReal *,void*),void**);
332 PETSC_EXTERN PetscErrorCode SNESComputeObjective(SNES,Vec,PetscReal *);
333 
334 /*E
335     SNESNormType - Norm that is passed in the Krylov convergence
336        test routines.
337 
338    Level: advanced
339 
340    Support for these is highly dependent on the solver.
341 
342    Notes:
343    This is primarily used to turn off extra norm and function computation
344    when the solvers are composed.
345 
346 .seealso: SNESSolve(), SNESGetConvergedReason(), KSPSetNormType(),
347           KSPSetConvergenceTest(), KSPSetPCSide()
348 E*/
349 
350 typedef enum {SNES_NORM_DEFAULT            = -1,
351               SNES_NORM_NONE               =  0,
352               SNES_NORM_FUNCTION           =  1,
353               SNES_NORM_INITIAL_ONLY       =  2,
354               SNES_NORM_FINAL_ONLY         =  3,
355               SNES_NORM_INITIAL_FINAL_ONLY =  4} SNESNormType;
356 PETSC_EXTERN const char *const*const SNESNormTypes;
357 /*MC
358     SNES_NORM_NONE - Don't compute function and its L2 norm.
359 
360    Level: advanced
361 
362     Notes:
363     This is most useful for stationary solvers with a fixed number of iterations used as smoothers.
364 
365 .seealso: SNESNormType, SNESSetNormType(), SNES_NORM_DEFAULT
366 M*/
367 
368 /*MC
369     SNES_NORM_FUNCTION - Compute the function and its L2 norm at each iteration.
370 
371    Level: advanced
372 
373     Notes:
374     Most solvers will use this no matter what norm type is passed to them.
375 
376 .seealso: SNESNormType, SNESSetNormType(), SNES_NORM_NONE
377 M*/
378 
379 /*MC
380     SNES_NORM_INITIAL_ONLY - Compute the function and its L2 at iteration 0, but do not update it.
381 
382    Level: advanced
383 
384    Notes:
385    This method is useful in composed methods, when a true solution might actually be found before SNESSolve() is called.
386    This option enables the solve to abort on the zeroth iteration if this is the case.
387 
388    For solvers that require the computation of the L2 norm of the function as part of the method, this merely cancels
389    the norm computation at the last iteration (if possible).
390 
391 .seealso: SNESNormType, SNESSetNormType(), SNES_NORM_FINAL_ONLY, SNES_NORM_INITIAL_FINAL_ONLY
392 M*/
393 
394 /*MC
395     SNES_NORM_FINAL_ONLY - Compute the function and its L2 norm on only the final iteration.
396 
397    Level: advanced
398 
399    Notes:
400    For solvers that require the computation of the L2 norm of the function as part of the method, behaves
401    exactly as SNES_NORM_DEFAULT.  This method is useful when the function is gotten after SNESSolve and
402    used in subsequent computation for methods that do not need the norm computed during the rest of the
403    solution procedure.
404 
405 .seealso: SNESNormType, SNESSetNormType(), SNES_NORM_INITIAL_ONLY, SNES_NORM_INITIAL_FINAL_ONLY
406 M*/
407 
408 /*MC
409     SNES_NORM_INITIAL_FINAL_ONLY - Compute the function and its L2 norm on only the initial and final iterations.
410 
411    Level: advanced
412 
413    Notes:
414    This method combines the benefits of SNES_NORM_INITIAL_ONLY and SNES_NORM_FINAL_ONLY.
415 
416 .seealso: SNESNormType, SNESSetNormType(), SNES_NORM_SNES_NORM_INITIAL_ONLY, SNES_NORM_FINAL_ONLY
417 M*/
418 
419 
420 PETSC_EXTERN PetscErrorCode SNESSetNormType(SNES,SNESNormType);
421 PETSC_EXTERN PetscErrorCode SNESGetNormType(SNES,SNESNormType*);
422 
423 PETSC_EXTERN PetscErrorCode SNESSetGS(SNES,PetscErrorCode (*SNESGSFunction)(SNES,Vec,Vec,void*),void*);
424 PETSC_EXTERN PetscErrorCode SNESGetGS(SNES,PetscErrorCode (**SNESGSFunction)(SNES,Vec,Vec,void*),void**);
425 PETSC_EXTERN PetscErrorCode SNESSetUseGS(SNES,PetscBool);
426 PETSC_EXTERN PetscErrorCode SNESGetUseGS(SNES,PetscBool *);
427 PETSC_EXTERN PetscErrorCode SNESComputeGS(SNES,Vec,Vec);
428 
429 PETSC_EXTERN PetscErrorCode SNESGSSetSweeps(SNES,PetscInt);
430 PETSC_EXTERN PetscErrorCode SNESGSGetSweeps(SNES,PetscInt *);
431 PETSC_EXTERN PetscErrorCode SNESGSSetTolerances(SNES,PetscReal,PetscReal,PetscReal,PetscInt);
432 PETSC_EXTERN PetscErrorCode SNESGSGetTolerances(SNES,PetscReal*,PetscReal*,PetscReal*,PetscInt*);
433 
434 PETSC_EXTERN PetscErrorCode SNESUpdateCheckJacobian(SNES,PetscInt);
435 
436 PETSC_EXTERN PetscErrorCode SNESShellGetContext(SNES,void**);
437 PETSC_EXTERN PetscErrorCode SNESShellSetContext(SNES,void*);
438 PETSC_EXTERN PetscErrorCode SNESShellSetSolve(SNES,PetscErrorCode (*)(SNES,Vec));
439 
440 /* --------- Routines specifically for line search methods --------------- */
441 
442 typedef struct _p_LineSearch* SNESLineSearch;
443 
444 /*S
445      SNESLineSearch - Abstract PETSc object that manages line-search operations
446 
447    Level: beginner
448 
449   Concepts: nonlinear solvers, line search
450 
451 .seealso:  SNESLineSearchCreate(), SNESLineSearchSetType(), SNES
452 S*/
453 
454 /*J
455     SNESLineSearchType - String with the name of a PETSc line search method
456 
457    Level: beginner
458 
459 .seealso: SNESLineSearchSetType(), SNES
460 J*/
461 
462 typedef const char* SNESLineSearchType;
463 #define SNESLINESEARCHBT                 "bt"
464 #define SNESLINESEARCHBASIC              "basic"
465 #define SNESLINESEARCHL2                 "l2"
466 #define SNESLINESEARCHCP                 "cp"
467 #define SNESLINESEARCHSHELL              "shell"
468 
469 PETSC_EXTERN PetscBool         SNESRegisterAllCalled;
470 PETSC_EXTERN PetscFunctionList SNESList;
471 PETSC_EXTERN PetscClassId      SNESLINESEARCH_CLASSID;
472 PETSC_EXTERN PetscBool         SNESLineSearchRegisterAllCalled;
473 PETSC_EXTERN PetscFunctionList SNESLineSearchList;
474 PETSC_EXTERN PetscLogEvent     SNESLineSearch_Apply;
475 
476 #define SNES_LINESEARCH_ORDER_LINEAR    1
477 #define SNES_LINESEARCH_ORDER_QUADRATIC 2
478 #define SNES_LINESEARCH_ORDER_CUBIC     3
479 
480 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode (*SNESLineSearchVIProjectFunc)(SNES,Vec);
481 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode (*SNESLineSearchVINormFunc)(SNES,Vec,Vec,PetscReal *);
482 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode (*SNESLineSearchApplyFunc)(SNESLineSearch);
483 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode (*SNESLineSearchUserFunc)(SNESLineSearch, void *);
484 
485 PETSC_EXTERN PetscErrorCode SNESLineSearchCreate(MPI_Comm, SNESLineSearch*);
486 PETSC_EXTERN PetscErrorCode SNESLineSearchReset(SNESLineSearch);
487 PETSC_EXTERN PetscErrorCode SNESLineSearchView(SNESLineSearch,PetscViewer);
488 PETSC_EXTERN PetscErrorCode SNESLineSearchDestroy(SNESLineSearch *);
489 PETSC_EXTERN PetscErrorCode SNESLineSearchSetType(SNESLineSearch, SNESLineSearchType);
490 PETSC_EXTERN PetscErrorCode SNESLineSearchSetFromOptions(SNESLineSearch);
491 PETSC_EXTERN PetscErrorCode SNESLineSearchSetUp(SNESLineSearch);
492 PETSC_EXTERN PetscErrorCode SNESLineSearchApply(SNESLineSearch, Vec, Vec, PetscReal *, Vec);
493 PETSC_EXTERN PetscErrorCode SNESLineSearchPreCheck(SNESLineSearch,Vec,Vec,PetscBool *);
494 PETSC_EXTERN PetscErrorCode SNESLineSearchPostCheck(SNESLineSearch,Vec,Vec,Vec,PetscBool *,PetscBool *);
495 PETSC_EXTERN PetscErrorCode SNESLineSearchSetWorkVecs(SNESLineSearch, PetscInt);
496 
497 /* set the functions for precheck and postcheck */
498 
499 PETSC_EXTERN PetscErrorCode SNESLineSearchSetPreCheck(SNESLineSearch, PetscErrorCode (*SNESLineSearchPreCheckFunction)(SNESLineSearch,Vec,Vec,PetscBool*,void*), void *ctx);
500 PETSC_EXTERN PetscErrorCode SNESLineSearchSetPostCheck(SNESLineSearch, PetscErrorCode (*SNESLineSearchPostCheckFunction)(SNESLineSearch,Vec,Vec,Vec,PetscBool *,PetscBool *,void*), void *ctx);
501 
502 PETSC_EXTERN PetscErrorCode SNESLineSearchGetPreCheck(SNESLineSearch, PetscErrorCode (**SNESLineSearchPreCheckFunction)(SNESLineSearch,Vec,Vec,PetscBool*,void*), void **ctx);
503 PETSC_EXTERN PetscErrorCode SNESLineSearchGetPostCheck(SNESLineSearch, PetscErrorCode (**SNESLineSearchPostCheckFunction)(SNESLineSearch,Vec,Vec,Vec,PetscBool *,PetscBool *,void*), void **ctx);
504 
505 /* set the functions for VI-specific line search operations */
506 
507 PETSC_EXTERN PetscErrorCode SNESLineSearchSetVIFunctions(SNESLineSearch, SNESLineSearchVIProjectFunc, SNESLineSearchVINormFunc);
508 PETSC_EXTERN PetscErrorCode SNESLineSearchGetVIFunctions(SNESLineSearch, SNESLineSearchVIProjectFunc*, SNESLineSearchVINormFunc*);
509 
510 /* pointers to the associated SNES in order to be able to get the function evaluation out */
511 PETSC_EXTERN PetscErrorCode SNESLineSearchSetSNES(SNESLineSearch,SNES);
512 PETSC_EXTERN PetscErrorCode SNESLineSearchGetSNES(SNESLineSearch,SNES*);
513 
514 /* set and get the parameters and vectors */
515 PETSC_EXTERN PetscErrorCode SNESLineSearchGetTolerances(SNESLineSearch,PetscReal*,PetscReal*,PetscReal*,PetscReal*,PetscReal*,PetscInt*);
516 PETSC_EXTERN PetscErrorCode SNESLineSearchSetTolerances(SNESLineSearch,PetscReal,PetscReal,PetscReal,PetscReal,PetscReal,PetscInt);
517 
518 PETSC_EXTERN PetscErrorCode SNESLineSearchPreCheckPicard(SNESLineSearch,Vec,Vec,PetscBool*,void*);
519 
520 PETSC_EXTERN PetscErrorCode SNESLineSearchGetLambda(SNESLineSearch,PetscReal*);
521 PETSC_EXTERN PetscErrorCode SNESLineSearchSetLambda(SNESLineSearch,PetscReal);
522 
523 PETSC_EXTERN PetscErrorCode SNESLineSearchGetDamping(SNESLineSearch,PetscReal*);
524 PETSC_EXTERN PetscErrorCode SNESLineSearchSetDamping(SNESLineSearch,PetscReal);
525 
526 PETSC_EXTERN PetscErrorCode SNESLineSearchGetOrder(SNESLineSearch,PetscInt *order);
527 PETSC_EXTERN PetscErrorCode SNESLineSearchSetOrder(SNESLineSearch,PetscInt order);
528 
529 PETSC_EXTERN PetscErrorCode SNESLineSearchGetSuccess(SNESLineSearch, PetscBool*);
530 PETSC_EXTERN PetscErrorCode SNESLineSearchSetSuccess(SNESLineSearch, PetscBool);
531 
532 PETSC_EXTERN PetscErrorCode SNESLineSearchGetVecs(SNESLineSearch,Vec*,Vec*,Vec*,Vec*,Vec*);
533 PETSC_EXTERN PetscErrorCode SNESLineSearchSetVecs(SNESLineSearch,Vec,Vec,Vec,Vec,Vec);
534 
535 PETSC_EXTERN PetscErrorCode SNESLineSearchGetNorms(SNESLineSearch, PetscReal *, PetscReal *, PetscReal *);
536 PETSC_EXTERN PetscErrorCode SNESLineSearchSetNorms(SNESLineSearch, PetscReal, PetscReal, PetscReal);
537 PETSC_EXTERN PetscErrorCode SNESLineSearchComputeNorms(SNESLineSearch);
538 PETSC_EXTERN PetscErrorCode SNESLineSearchSetComputeNorms(SNESLineSearch, PetscBool);
539 
540 PETSC_EXTERN PetscErrorCode SNESLineSearchSetMonitor(SNESLineSearch, PetscBool);
541 PETSC_EXTERN PetscErrorCode SNESLineSearchGetMonitor(SNESLineSearch, PetscViewer*);
542 
543 PETSC_EXTERN PetscErrorCode SNESLineSearchAppendOptionsPrefix(SNESLineSearch, const char prefix[]);
544 PETSC_EXTERN PetscErrorCode SNESLineSearchGetOptionsPrefix(SNESLineSearch, const char *prefix[]);
545 
546 
547 /* Shell interface functions */
548 PETSC_EXTERN PetscErrorCode SNESLineSearchShellSetUserFunc(SNESLineSearch,SNESLineSearchUserFunc,void*);
549 PETSC_EXTERN PetscErrorCode SNESLineSearchShellGetUserFunc(SNESLineSearch,SNESLineSearchUserFunc*,void**);
550 
551 /* BT interface functions */
552 PETSC_EXTERN PetscErrorCode SNESLineSearchBTSetAlpha(SNESLineSearch, PetscReal);
553 PETSC_EXTERN PetscErrorCode SNESLineSearchBTGetAlpha(SNESLineSearch, PetscReal*);
554 
555 /*register line search types */
556 PETSC_EXTERN PetscErrorCode SNESLineSearchRegister(const char[],PetscErrorCode(*)(SNESLineSearch));
557 PETSC_EXTERN PetscErrorCode SNESLineSearchRegisterAll(void);
558 
559 /* Routines for VI solver */
560 PETSC_EXTERN PetscErrorCode SNESVISetVariableBounds(SNES,Vec,Vec);
561 PETSC_EXTERN PetscErrorCode SNESVISetComputeVariableBounds(SNES, PetscErrorCode (*)(SNES,Vec,Vec));
562 PETSC_EXTERN PetscErrorCode SNESVIGetInactiveSet(SNES,IS*);
563 PETSC_EXTERN PetscErrorCode SNESVIGetActiveSetIS(SNES,Vec,Vec,IS*);
564 PETSC_EXTERN PetscErrorCode SNESVIComputeInactiveSetFnorm(SNES,Vec,Vec,PetscReal*);
565 PETSC_EXTERN PetscErrorCode SNESVISetRedundancyCheck(SNES,PetscErrorCode(*)(SNES,IS,IS*,void*),void*);
566 #define SNES_VI_INF   1.0e20
567 #define SNES_VI_NINF -1.0e20
568 
569 PETSC_EXTERN PetscErrorCode SNESTestLocalMin(SNES);
570 
571 /* Should this routine be private? */
572 PETSC_EXTERN PetscErrorCode SNESComputeJacobian(SNES,Vec,Mat*,Mat*,MatStructure*);
573 
574 PETSC_EXTERN PetscErrorCode SNESSetDM(SNES,DM);
575 PETSC_EXTERN PetscErrorCode SNESGetDM(SNES,DM*);
576 PETSC_EXTERN PetscErrorCode SNESSetPC(SNES,SNES);
577 PETSC_EXTERN PetscErrorCode SNESGetPC(SNES,SNES*);
578 PETSC_EXTERN PetscErrorCode SNESSetPCSide(SNES,PCSide);
579 PETSC_EXTERN PetscErrorCode SNESGetPCSide(SNES,PCSide*);
580 PETSC_EXTERN PetscErrorCode SNESSetLineSearch(SNES,SNESLineSearch);
581 PETSC_EXTERN PetscErrorCode SNESGetLineSearch(SNES,SNESLineSearch*);
582 PETSC_EXTERN PetscErrorCode SNESRestrictHookAdd(SNES,PetscErrorCode (*)(SNES,SNES,void*),void*);
583 PETSC_EXTERN PetscErrorCode SNESRestrictHooksRun(SNES,SNES);
584 
585 PETSC_DEPRECATED("Use SNESGetLineSearch()") PETSC_STATIC_INLINE PetscErrorCode SNESGetSNESLineSearch(SNES snes,SNESLineSearch *ls) {return SNESGetLineSearch(snes,ls);}
586 PETSC_DEPRECATED("Use SNESSetLineSearch()") PETSC_STATIC_INLINE PetscErrorCode SNESSetSNESLineSearch(SNES snes,SNESLineSearch ls) {return SNESSetLineSearch(snes,ls);}
587 
588 PETSC_EXTERN PetscErrorCode SNESSetUpMatrices(SNES);
589 PETSC_EXTERN PetscErrorCode DMSNESSetFunction(DM,PetscErrorCode(*SNESFunction)(SNES,Vec,Vec,void*),void*);
590 PETSC_EXTERN PetscErrorCode DMSNESGetFunction(DM,PetscErrorCode(**SNESSetFunction)(SNES,Vec,Vec,void*),void**);
591 PETSC_EXTERN PetscErrorCode DMSNESSetGS(DM,PetscErrorCode(*SNESGSFunction)(SNES,Vec,Vec,void*),void*);
592 PETSC_EXTERN PetscErrorCode DMSNESGetGS(DM,PetscErrorCode(**SNESGSFunction)(SNES,Vec,Vec,void*),void**);
593 PETSC_EXTERN PetscErrorCode DMSNESSetJacobian(DM,PetscErrorCode(*SNESJacobianFunction)(SNES,Vec,Mat*,Mat*,MatStructure*,void*),void*);
594 PETSC_EXTERN PetscErrorCode DMSNESGetJacobian(DM,PetscErrorCode(**SNESJacobianFunction)(SNES,Vec,Mat*,Mat*,MatStructure*,void*),void**);
595 PETSC_EXTERN PetscErrorCode DMSNESSetPicard(DM,PetscErrorCode(*SNESFunction)(SNES,Vec,Vec,void*),PetscErrorCode(*SNESJacobianFunction)(SNES,Vec,Mat*,Mat*,MatStructure*,void*),void*);
596 PETSC_EXTERN PetscErrorCode DMSNESGetPicard(DM,PetscErrorCode(**SNESFunction)(SNES,Vec,Vec,void*),PetscErrorCode(**SNESJacobianFunction)(SNES,Vec,Mat*,Mat*,MatStructure*,void*),void**);
597 PETSC_EXTERN PetscErrorCode DMSNESSetObjective(DM,PetscErrorCode (*SNESObjectiveFunction)(SNES,Vec,PetscReal *,void*),void*);
598 PETSC_EXTERN PetscErrorCode DMSNESGetObjective(DM,PetscErrorCode (**SNESObjectiveFunction)(SNES,Vec,PetscReal *,void*),void**);
599 
600 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode (*DMDASNESFunction)(DMDALocalInfo*,void*,void*,void*);
601 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode (*DMDASNESJacobian)(DMDALocalInfo*,void*,Mat,Mat,MatStructure*,void*);
602 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode (*DMDASNESObjective)(DMDALocalInfo*,void*,PetscReal*,void*);
603 
604 PETSC_EXTERN PetscErrorCode DMDASNESSetFunctionLocal(DM,InsertMode,DMDASNESFunction,void*);
605 PETSC_EXTERN PetscErrorCode DMDASNESSetJacobianLocal(DM,DMDASNESJacobian,void*);
606 PETSC_EXTERN PetscErrorCode DMDASNESSetObjectiveLocal(DM,DMDASNESObjective,void*);
607 PETSC_EXTERN PetscErrorCode DMDASNESSetPicardLocal(DM,InsertMode,PetscErrorCode (*)(DMDALocalInfo*,void*,void*,void*),PetscErrorCode (*)(DMDALocalInfo*,void*,Mat,Mat,MatStructure*,void*),void*);
608 
609 PETSC_EXTERN PetscErrorCode DMSNESSetFunctionLocal(DM,PetscErrorCode (*)(DM,Vec,Vec,void*),void*);
610 PETSC_EXTERN PetscErrorCode DMSNESSetJacobianLocal(DM,PetscErrorCode (*)(DM,Vec,Mat,Mat,MatStructure*,void*),void*);
611 
612 /* Routines for Multiblock solver */
613 PETSC_EXTERN PetscErrorCode SNESMultiblockSetFields(SNES, const char [], PetscInt, const PetscInt *);
614 PETSC_EXTERN PetscErrorCode SNESMultiblockSetIS(SNES, const char [], IS);
615 PETSC_EXTERN PetscErrorCode SNESMultiblockSetBlockSize(SNES, PetscInt);
616 PETSC_EXTERN PetscErrorCode SNESMultiblockSetType(SNES, PCCompositeType);
617 
618 /*J
619     SNESMSType - String with the name of a PETSc SNESMS method.
620 
621    Level: intermediate
622 
623 .seealso: SNESMSSetType(), SNES
624 J*/
625 typedef const char* SNESMSType;
626 #define SNESMSM62       "m62"
627 #define SNESMSEULER     "euler"
628 #define SNESMSJAMESON83 "jameson83"
629 #define SNESMSVLTP21    "vltp21"
630 #define SNESMSVLTP31    "vltp31"
631 #define SNESMSVLTP41    "vltp41"
632 #define SNESMSVLTP51    "vltp51"
633 #define SNESMSVLTP61    "vltp61"
634 
635 PETSC_EXTERN PetscErrorCode SNESMSRegister(SNESMSType,PetscInt,PetscInt,PetscReal,const PetscReal[],const PetscReal[],const PetscReal[]);
636 PETSC_EXTERN PetscErrorCode SNESMSSetType(SNES,SNESMSType);
637 PETSC_EXTERN PetscErrorCode SNESMSFinalizePackage(void);
638 PETSC_EXTERN PetscErrorCode SNESMSInitializePackage(void);
639 PETSC_EXTERN PetscErrorCode SNESMSRegisterDestroy(void);
640 PETSC_EXTERN PetscErrorCode SNESMSRegisterAll(void);
641 
642 /* routines for NGMRES solver */
643 
644 typedef enum {
645   SNES_NGMRES_RESTART_NONE       = 0,
646   SNES_NGMRES_RESTART_PERIODIC   = 1,
647   SNES_NGMRES_RESTART_DIFFERENCE = 2} SNESNGMRESRestartType;
648 PETSC_EXTERN const char *const SNESNGMRESRestartTypes[];
649 
650 typedef enum {
651   SNES_NGMRES_SELECT_NONE       = 0,
652   SNES_NGMRES_SELECT_DIFFERENCE = 1,
653   SNES_NGMRES_SELECT_LINESEARCH = 2} SNESNGMRESSelectType;
654 PETSC_EXTERN const char *const SNESNGMRESSelectTypes[];
655 
656 PETSC_EXTERN PetscErrorCode SNESNGMRESSetRestartType(SNES, SNESNGMRESRestartType);
657 PETSC_EXTERN PetscErrorCode SNESNGMRESSetSelectType(SNES, SNESNGMRESSelectType);
658 
659 /* routines for NCG solver */
660 
661 typedef enum {
662   SNES_NCG_FR    = 0,
663   SNES_NCG_PRP   = 1,
664   SNES_NCG_HS    = 2,
665   SNES_NCG_DY    = 3,
666   SNES_NCG_CD    = 4} SNESNCGType;
667 PETSC_EXTERN const char *const SNESNCGTypes[];
668 
669 PETSC_EXTERN PetscErrorCode SNESNCGSetType(SNES, SNESNCGType);
670 
671 typedef enum {SNES_QN_SCALE_NONE       = 0,
672               SNES_QN_SCALE_SHANNO     = 1,
673               SNES_QN_SCALE_LINESEARCH = 2,
674               SNES_QN_SCALE_JACOBIAN   = 3} SNESQNScaleType;
675 PETSC_EXTERN const char *const SNESQNScaleTypes[];
676 typedef enum {SNES_QN_RESTART_NONE     = 0,
677               SNES_QN_RESTART_POWELL   = 1,
678               SNES_QN_RESTART_PERIODIC = 2} SNESQNRestartType;
679 PETSC_EXTERN const char *const SNESQNRestartTypes[];
680 
681 PETSC_EXTERN PetscErrorCode SNESQNSetScaleType(SNES, SNESQNScaleType);
682 PETSC_EXTERN PetscErrorCode SNESQNSetRestartType(SNES, SNESQNRestartType);
683 
684 PETSC_EXTERN PetscErrorCode SNESNASMGetSubdomains(SNES,PetscInt*,SNES**,VecScatter**,VecScatter**,VecScatter**);
685 PETSC_EXTERN PetscErrorCode SNESNASMSetSubdomains(SNES,PetscInt,SNES*,VecScatter*,VecScatter*,VecScatter*);
686 PETSC_EXTERN PetscErrorCode SNESNASMSetDamping(SNES,PetscReal);
687 PETSC_EXTERN PetscErrorCode SNESNASMGetDamping(SNES,PetscReal*);
688 PETSC_EXTERN PetscErrorCode SNESNASMGetSubdomainVecs(SNES,PetscInt*,Vec**,Vec**,Vec**,Vec**);
689 PETSC_EXTERN PetscErrorCode SNESNASMSetComputeFinalJacobian(SNES,PetscBool);
690 
691 #endif
692