xref: /petsc/include/petscsnes.h (revision df4cd43f92eaa320656440c40edb1046daee8f75)
1 /*
2     User interface for the nonlinear solvers package.
3 */
4 #ifndef PETSCSNES_H
5 #define PETSCSNES_H
6 
7 #include <petscksp.h>
8 #include <petscdmtypes.h>
9 #include <petscfvtypes.h>
10 #include <petscdmdatypes.h>
11 
12 /* SUBMANSEC = SNES */
13 
14 /*S
15      SNES - Abstract PETSc object that manages all nonlinear solves
16 
17    Level: beginner
18 
19 .seealso: [](chapter_snes), `SNESCreate()`, `SNESSetType()`, `SNESType`, `TS`, `SNES`, `KSP`, `PC`, `SNESDestroy()`
20 S*/
21 typedef struct _p_SNES *SNES;
22 
23 /*J
24     SNESType - String with the name of a PETSc SNES method.
25 
26    Level: beginner
27 
28 .seealso: [](chapter_snes), `SNESSetType()`, `SNES`, `SNESCreate()`, `SNESDestroy()`, `SNESSetFromOptions()`
29 J*/
30 typedef const char *SNESType;
31 #define SNESNEWTONLS         "newtonls"
32 #define SNESNEWTONTR         "newtontr"
33 #define SNESNEWTONTRDC       "newtontrdc"
34 #define SNESPYTHON           "python"
35 #define SNESNRICHARDSON      "nrichardson"
36 #define SNESKSPONLY          "ksponly"
37 #define SNESKSPTRANSPOSEONLY "ksptransposeonly"
38 #define SNESVINEWTONRSLS     "vinewtonrsls"
39 #define SNESVINEWTONSSLS     "vinewtonssls"
40 #define SNESNGMRES           "ngmres"
41 #define SNESQN               "qn"
42 #define SNESSHELL            "shell"
43 #define SNESNGS              "ngs"
44 #define SNESNCG              "ncg"
45 #define SNESFAS              "fas"
46 #define SNESMS               "ms"
47 #define SNESNASM             "nasm"
48 #define SNESANDERSON         "anderson"
49 #define SNESASPIN            "aspin"
50 #define SNESCOMPOSITE        "composite"
51 #define SNESPATCH            "patch"
52 
53 /* Logging support */
54 PETSC_EXTERN PetscClassId SNES_CLASSID;
55 PETSC_EXTERN PetscClassId DMSNES_CLASSID;
56 
57 PETSC_EXTERN PetscErrorCode SNESInitializePackage(void);
58 
59 PETSC_EXTERN PetscErrorCode SNESCreate(MPI_Comm, SNES *);
60 PETSC_EXTERN PetscErrorCode SNESReset(SNES);
61 PETSC_EXTERN PetscErrorCode SNESDestroy(SNES *);
62 PETSC_EXTERN PetscErrorCode SNESSetType(SNES, SNESType);
63 PETSC_EXTERN PetscErrorCode SNESMonitor(SNES, PetscInt, PetscReal);
64 PETSC_EXTERN PetscErrorCode SNESMonitorSet(SNES, PetscErrorCode (*)(SNES, PetscInt, PetscReal, void *), void *, PetscErrorCode (*)(void **));
65 PETSC_EXTERN PetscErrorCode SNESMonitorSetFromOptions(SNES, const char[], const char[], const char[], PetscErrorCode (*)(SNES, PetscInt, PetscReal, PetscViewerAndFormat *), PetscErrorCode (*)(SNES, PetscViewerAndFormat *));
66 PETSC_EXTERN PetscErrorCode SNESMonitorCancel(SNES);
67 PETSC_EXTERN PetscErrorCode SNESMonitorSAWs(SNES, PetscInt, PetscReal, void *);
68 PETSC_EXTERN PetscErrorCode SNESMonitorSAWsCreate(SNES, void **);
69 PETSC_EXTERN PetscErrorCode SNESMonitorSAWsDestroy(void **);
70 PETSC_EXTERN PetscErrorCode SNESSetConvergenceHistory(SNES, PetscReal[], PetscInt[], PetscInt, PetscBool);
71 PETSC_EXTERN PetscErrorCode SNESGetConvergenceHistory(SNES, PetscReal *[], PetscInt *[], PetscInt *);
72 PETSC_EXTERN PetscErrorCode SNESSetUp(SNES);
73 PETSC_EXTERN PetscErrorCode SNESSolve(SNES, Vec, Vec);
74 PETSC_EXTERN PetscErrorCode SNESSetErrorIfNotConverged(SNES, PetscBool);
75 PETSC_EXTERN PetscErrorCode SNESGetErrorIfNotConverged(SNES, PetscBool *);
76 
77 PETSC_EXTERN PetscErrorCode SNESSetWorkVecs(SNES, PetscInt);
78 
79 PETSC_EXTERN PetscErrorCode SNESAddOptionsChecker(PetscErrorCode (*)(SNES));
80 
81 PETSC_EXTERN PetscErrorCode SNESSetUpdate(SNES, PetscErrorCode (*)(SNES, PetscInt));
82 
83 PETSC_EXTERN PetscErrorCode SNESRegister(const char[], PetscErrorCode (*)(SNES));
84 
85 PETSC_EXTERN PetscErrorCode SNESGetKSP(SNES, KSP *);
86 PETSC_EXTERN PetscErrorCode SNESSetKSP(SNES, KSP);
87 PETSC_EXTERN PetscErrorCode SNESSetSolution(SNES, Vec);
88 PETSC_EXTERN PetscErrorCode SNESGetSolution(SNES, Vec *);
89 PETSC_EXTERN PetscErrorCode SNESGetSolutionUpdate(SNES, Vec *);
90 PETSC_EXTERN PetscErrorCode SNESGetRhs(SNES, Vec *);
91 PETSC_EXTERN PetscErrorCode SNESView(SNES, PetscViewer);
92 PETSC_EXTERN PetscErrorCode SNESLoad(SNES, PetscViewer);
93 PETSC_EXTERN PetscErrorCode SNESConvergedReasonViewSet(SNES, PetscErrorCode (*)(SNES, void *), void *, PetscErrorCode (*)(void **));
94 PETSC_EXTERN PetscErrorCode SNESViewFromOptions(SNES, PetscObject, const char[]);
95 PETSC_EXTERN PetscErrorCode SNESConvergedReasonView(SNES, PetscViewer);
96 PETSC_EXTERN PetscErrorCode SNESConvergedReasonViewFromOptions(SNES);
97 PETSC_EXTERN PetscErrorCode SNESConvergedReasonViewCancel(SNES);
98 
99 PETSC_DEPRECATED_FUNCTION("Use SNESConvergedReasonView() (since version 3.14)") static inline PetscErrorCode SNESReasonView(SNES snes, PetscViewer v)
100 {
101   return SNESConvergedReasonView(snes, v);
102 }
103 PETSC_DEPRECATED_FUNCTION("Use SNESConvergedReasonViewFromOptions() (since version 3.14)") static inline PetscErrorCode SNESReasonViewFromOptions(SNES snes)
104 {
105   return SNESConvergedReasonViewFromOptions(snes);
106 }
107 
108 #define SNES_FILE_CLASSID 1211224
109 
110 PETSC_EXTERN PetscErrorCode SNESSetOptionsPrefix(SNES, const char[]);
111 PETSC_EXTERN PetscErrorCode SNESAppendOptionsPrefix(SNES, const char[]);
112 PETSC_EXTERN PetscErrorCode SNESGetOptionsPrefix(SNES, const char *[]);
113 PETSC_EXTERN PetscErrorCode SNESSetFromOptions(SNES);
114 PETSC_EXTERN PetscErrorCode SNESResetFromOptions(SNES);
115 
116 PETSC_EXTERN PetscErrorCode SNESSetUseMatrixFree(SNES, PetscBool, PetscBool);
117 PETSC_EXTERN PetscErrorCode SNESGetUseMatrixFree(SNES, PetscBool *, PetscBool *);
118 PETSC_EXTERN PetscErrorCode MatCreateSNESMF(SNES, Mat *);
119 PETSC_EXTERN PetscErrorCode MatSNESMFGetSNES(Mat, SNES *);
120 PETSC_EXTERN PetscErrorCode MatSNESMFSetReuseBase(Mat, PetscBool);
121 PETSC_EXTERN PetscErrorCode MatSNESMFGetReuseBase(Mat, PetscBool *);
122 PETSC_EXTERN PetscErrorCode MatMFFDComputeJacobian(SNES, Vec, Mat, Mat, void *);
123 PETSC_EXTERN PetscErrorCode MatCreateSNESMFMore(SNES, Vec, Mat *);
124 PETSC_EXTERN PetscErrorCode MatSNESMFMoreSetParameters(Mat, PetscReal, PetscReal, PetscReal);
125 
126 PETSC_EXTERN PetscErrorCode SNESGetType(SNES, SNESType *);
127 PETSC_EXTERN PetscErrorCode SNESMonitorDefaultSetUp(SNES, PetscViewerAndFormat *);
128 PETSC_EXTERN PetscErrorCode SNESMonitorDefault(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
129 PETSC_EXTERN PetscErrorCode SNESMonitorScaling(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
130 PETSC_EXTERN PetscErrorCode SNESMonitorRange(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
131 PETSC_EXTERN PetscErrorCode SNESMonitorRatio(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
132 PETSC_EXTERN PetscErrorCode SNESMonitorRatioSetUp(SNES, PetscViewerAndFormat *);
133 PETSC_EXTERN PetscErrorCode SNESMonitorSolution(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
134 PETSC_EXTERN PetscErrorCode SNESMonitorResidual(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
135 PETSC_EXTERN PetscErrorCode SNESMonitorSolutionUpdate(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
136 PETSC_EXTERN PetscErrorCode SNESMonitorDefaultShort(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
137 PETSC_EXTERN PetscErrorCode SNESMonitorDefaultField(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
138 PETSC_EXTERN PetscErrorCode SNESMonitorJacUpdateSpectrum(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
139 PETSC_EXTERN PetscErrorCode SNESMonitorFields(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
140 PETSC_EXTERN PetscErrorCode KSPMonitorSNESResidual(KSP, PetscInt, PetscReal, PetscViewerAndFormat *);
141 PETSC_EXTERN PetscErrorCode KSPMonitorSNESResidualDrawLG(KSP, PetscInt, PetscReal, PetscViewerAndFormat *);
142 PETSC_EXTERN PetscErrorCode KSPMonitorSNESResidualDrawLGCreate(PetscViewer, PetscViewerFormat, void *, PetscViewerAndFormat **);
143 
144 PETSC_EXTERN PetscErrorCode SNESSetTolerances(SNES, PetscReal, PetscReal, PetscReal, PetscInt, PetscInt);
145 PETSC_EXTERN PetscErrorCode SNESSetDivergenceTolerance(SNES, PetscReal);
146 PETSC_EXTERN PetscErrorCode SNESGetTolerances(SNES, PetscReal *, PetscReal *, PetscReal *, PetscInt *, PetscInt *);
147 PETSC_EXTERN PetscErrorCode SNESGetDivergenceTolerance(SNES, PetscReal *);
148 PETSC_EXTERN PetscErrorCode SNESSetTrustRegionTolerance(SNES, PetscReal);
149 PETSC_EXTERN PetscErrorCode SNESGetForceIteration(SNES, PetscBool *);
150 PETSC_EXTERN PetscErrorCode SNESSetForceIteration(SNES, PetscBool);
151 PETSC_EXTERN PetscErrorCode SNESGetIterationNumber(SNES, PetscInt *);
152 PETSC_EXTERN PetscErrorCode SNESSetIterationNumber(SNES, PetscInt);
153 
154 PETSC_EXTERN PetscErrorCode SNESNewtonTRSetPreCheck(SNES, PetscErrorCode (*)(SNES, Vec, Vec, PetscBool *, void *), void *ctx);
155 PETSC_EXTERN PetscErrorCode SNESNewtonTRGetPreCheck(SNES, PetscErrorCode (**)(SNES, Vec, Vec, PetscBool *, void *), void **ctx);
156 PETSC_EXTERN PetscErrorCode SNESNewtonTRSetPostCheck(SNES, PetscErrorCode (*)(SNES, Vec, Vec, Vec, PetscBool *, PetscBool *, void *), void *ctx);
157 PETSC_EXTERN PetscErrorCode SNESNewtonTRGetPostCheck(SNES, PetscErrorCode (**)(SNES, Vec, Vec, Vec, PetscBool *, PetscBool *, void *), void **ctx);
158 
159 PETSC_EXTERN PetscErrorCode SNESNewtonTRDCGetRhoFlag(SNES, PetscBool *);
160 PETSC_EXTERN PetscErrorCode SNESNewtonTRDCSetPreCheck(SNES, PetscErrorCode (*)(SNES, Vec, Vec, PetscBool *, void *), void *ctx);
161 PETSC_EXTERN PetscErrorCode SNESNewtonTRDCGetPreCheck(SNES, PetscErrorCode (**)(SNES, Vec, Vec, PetscBool *, void *), void **ctx);
162 PETSC_EXTERN PetscErrorCode SNESNewtonTRDCSetPostCheck(SNES, PetscErrorCode (*)(SNES, Vec, Vec, Vec, PetscBool *, PetscBool *, void *), void *ctx);
163 PETSC_EXTERN PetscErrorCode SNESNewtonTRDCGetPostCheck(SNES, PetscErrorCode (**)(SNES, Vec, Vec, Vec, PetscBool *, PetscBool *, void *), void **ctx);
164 
165 PETSC_EXTERN PetscErrorCode SNESGetNonlinearStepFailures(SNES, PetscInt *);
166 PETSC_EXTERN PetscErrorCode SNESSetMaxNonlinearStepFailures(SNES, PetscInt);
167 PETSC_EXTERN PetscErrorCode SNESGetMaxNonlinearStepFailures(SNES, PetscInt *);
168 PETSC_EXTERN PetscErrorCode SNESGetNumberFunctionEvals(SNES, PetscInt *);
169 
170 PETSC_EXTERN PetscErrorCode SNESSetLagPreconditioner(SNES, PetscInt);
171 PETSC_EXTERN PetscErrorCode SNESGetLagPreconditioner(SNES, PetscInt *);
172 PETSC_EXTERN PetscErrorCode SNESSetLagJacobian(SNES, PetscInt);
173 PETSC_EXTERN PetscErrorCode SNESGetLagJacobian(SNES, PetscInt *);
174 PETSC_EXTERN PetscErrorCode SNESSetLagPreconditionerPersists(SNES, PetscBool);
175 PETSC_EXTERN PetscErrorCode SNESSetLagJacobianPersists(SNES, PetscBool);
176 PETSC_EXTERN PetscErrorCode SNESSetGridSequence(SNES, PetscInt);
177 PETSC_EXTERN PetscErrorCode SNESGetGridSequence(SNES, PetscInt *);
178 
179 PETSC_EXTERN PetscErrorCode SNESGetLinearSolveIterations(SNES, PetscInt *);
180 PETSC_EXTERN PetscErrorCode SNESGetLinearSolveFailures(SNES, PetscInt *);
181 PETSC_EXTERN PetscErrorCode SNESSetMaxLinearSolveFailures(SNES, PetscInt);
182 PETSC_EXTERN PetscErrorCode SNESGetMaxLinearSolveFailures(SNES, PetscInt *);
183 PETSC_EXTERN PetscErrorCode SNESSetCountersReset(SNES, PetscBool);
184 
185 PETSC_EXTERN PetscErrorCode SNESKSPSetUseEW(SNES, PetscBool);
186 PETSC_EXTERN PetscErrorCode SNESKSPGetUseEW(SNES, PetscBool *);
187 PETSC_EXTERN PetscErrorCode SNESKSPSetParametersEW(SNES, PetscInt, PetscReal, PetscReal, PetscReal, PetscReal, PetscReal, PetscReal);
188 PETSC_EXTERN PetscErrorCode SNESKSPGetParametersEW(SNES, PetscInt *, PetscReal *, PetscReal *, PetscReal *, PetscReal *, PetscReal *, PetscReal *);
189 
190 #include <petscdrawtypes.h>
191 PETSC_EXTERN PetscErrorCode SNESMonitorLGRange(SNES, PetscInt, PetscReal, void *);
192 
193 PETSC_EXTERN PetscErrorCode SNESSetApplicationContext(SNES, void *);
194 PETSC_EXTERN PetscErrorCode SNESGetApplicationContext(SNES, void *);
195 PETSC_EXTERN PetscErrorCode SNESSetComputeApplicationContext(SNES, PetscErrorCode (*)(SNES, void **), PetscErrorCode (*)(void **));
196 
197 PETSC_EXTERN PetscErrorCode SNESPythonSetType(SNES, const char[]);
198 PETSC_EXTERN PetscErrorCode SNESPythonGetType(SNES, const char *[]);
199 
200 PETSC_EXTERN PetscErrorCode SNESSetFunctionDomainError(SNES);
201 PETSC_EXTERN PetscErrorCode SNESGetFunctionDomainError(SNES, PetscBool *);
202 PETSC_EXTERN PetscErrorCode SNESGetJacobianDomainError(SNES, PetscBool *);
203 PETSC_EXTERN PetscErrorCode SNESSetJacobianDomainError(SNES);
204 PETSC_EXTERN PetscErrorCode SNESSetCheckJacobianDomainError(SNES, PetscBool);
205 PETSC_EXTERN PetscErrorCode SNESGetCheckJacobianDomainError(SNES, PetscBool *);
206 
207 #define SNES_CONVERGED_TR_DELTA_DEPRECATED SNES_CONVERGED_TR_DELTA PETSC_DEPRECATED_ENUM("Use SNES_DIVERGED_TR_DELTA (since version 3.12)")
208 /*E
209     SNESConvergedReason - reason a `SNESSolve()` was determined to have converged or diverged
210 
211    Level: beginner
212 
213    Values:
214 +  `SNES_CONVERGED_FNORM_ABS` - 2-norm(F) <= abstol
215 .  `SNES_CONVERGED_FNORM_RELATIVE` - 2-norm(F) <= rtol*2-norm(F(x_0)) where x_0 is the initial guess
216 .  `SNES_CONVERGED_SNORM_RELATIVE` - The 2-norm of the last step <= stol * 2-norm(x) where x is the current
217 .  `SNES_DIVERGED_FUNCTION_COUNT` - The user provided function has been called more times than the maximum set in `SNESSetTolerances()`
218 .  `SNES_DIVERGED_DTOL` - The norm of the function has increased by a factor of divtol set with `SNESSetDivergenceTolerance()`
219 .  `SNES_DIVERGED_FNORM_NAN` - the 2-norm of the current function evaluation is not-a-number (NaN), this
220       is usually caused by a division of 0 by 0.
221 .  `SNES_DIVERGED_MAX_IT` - `SNESSolve()` has reached the maximum number of iterations requested
222 .  `SNES_DIVERGED_LINE_SEARCH` - The line search has failed. This only occurs for `SNES` solvers that use a line search
223 .  `SNES_DIVERGED_LOCAL_MIN` - the algorithm seems to have stagnated at a local minimum that is not zero.
224 -  `SNES_CONERGED_ITERATING` - this only occurs if `SNESGetConvergedReason()` is called during the `SNESSolve()`
225 
226     Notes:
227    The two most common reasons for divergence are an incorrectly coded or computed Jacobian or failure or lack of convergence in the linear system (in this case we recommend
228    testing with `-pc_type lu` to eliminate the linear solver as the cause of the problem).
229 
230    `SNES_DIVERGED_LOCAL_MIN` can only occur when using the line-search variant of `SNES`.
231        The line search wants to minimize Q(alpha) = 1/2 || F(x + alpha s) ||^2_2  this occurs
232        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
233        you get Q'(alpha) = -F(x)^T F'(x)^(-1)^T F'(x+alpha s)F(x+alpha s); when alpha = 0
234        Q'(0) = - ||F(x)||^2_2 which is always NEGATIVE if F'(x) is invertible. This means the Newton
235        direction is a descent direction and the line search should succeed if alpha is small enough.
236 
237        If F'(x) is NOT invertible AND F'(x)^T F(x) = 0 then Q'(0) = 0 and the Newton direction
238        is NOT a descent direction so the line search will fail. All one can do at this point
239        is change the initial guess and try again.
240 
241        An alternative explanation: Newton's method can be regarded as replacing the function with
242        its linear approximation and minimizing the 2-norm of that. That is F(x+s) approx F(x) + F'(x)s
243        so we minimize || F(x) + F'(x) s ||^2_2; do this using Least Squares. If F'(x) is invertible then
244        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
245        exists a nontrivial (that is F'(x)s != 0) solution to the equation and this direction is
246        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)
247        = - (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
248        and F'(x)^T F'(x) has no negative eigenvalues Q'(0) < 0 so s is a descent direction and the line
249        search should succeed for small enough alpha.
250 
251        Note that this RARELY happens in practice. Far more likely the linear system is not being solved
252        (well enough?) or the Jacobian is wrong.
253 
254    `SNES_DIVERGED_MAX_IT` means that the solver reached the maximum number of iterations without satisfying any
255    convergence criteria. `SNES_CONVERGED_ITS` means that `SNESConvergedSkip()` was chosen as the convergence test;
256    thus the usual convergence criteria have not been checked and may or may not be satisfied.
257 
258 .seealso: [](chapter_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `KSPConvergedReason`, `SNESSetConvergenceTest()`, `SNESSetTolerances()`
259 E*/
260 typedef enum {                       /* converged */
261   SNES_CONVERGED_FNORM_ABS      = 2, /* ||F|| < atol */
262   SNES_CONVERGED_FNORM_RELATIVE = 3, /* ||F|| < rtol*||F_initial|| */
263   SNES_CONVERGED_SNORM_RELATIVE = 4, /* Newton computed step size small; || delta x || < stol || x ||*/
264   SNES_CONVERGED_ITS            = 5, /* maximum iterations reached */
265   SNES_BREAKOUT_INNER_ITER      = 6, /* Flag to break out of inner loop after checking custom convergence. */
266                                      /* it is used in multi-phase flow when state changes */
267   /* diverged */
268   SNES_DIVERGED_FUNCTION_DOMAIN      = -1, /* the new x location passed the function is not in the domain of F */
269   SNES_DIVERGED_FUNCTION_COUNT       = -2,
270   SNES_DIVERGED_LINEAR_SOLVE         = -3, /* the linear solve failed */
271   SNES_DIVERGED_FNORM_NAN            = -4,
272   SNES_DIVERGED_MAX_IT               = -5,
273   SNES_DIVERGED_LINE_SEARCH          = -6,  /* the line search failed */
274   SNES_DIVERGED_INNER                = -7,  /* inner solve failed */
275   SNES_DIVERGED_LOCAL_MIN            = -8,  /* || J^T b || is small, implies converged to local minimum of F() */
276   SNES_DIVERGED_DTOL                 = -9,  /* || F || > divtol*||F_initial|| */
277   SNES_DIVERGED_JACOBIAN_DOMAIN      = -10, /* Jacobian calculation does not make sense */
278   SNES_DIVERGED_TR_DELTA             = -11,
279   SNES_CONVERGED_TR_DELTA_DEPRECATED = -11,
280 
281   SNES_CONVERGED_ITERATING = 0
282 } SNESConvergedReason;
283 PETSC_EXTERN const char *const *SNESConvergedReasons;
284 
285 /*MC
286      SNES_CONVERGED_FNORM_ABS - 2-norm(F) <= abstol
287 
288    Level: beginner
289 
290 .seealso: [](chapter_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`
291 M*/
292 
293 /*MC
294      SNES_CONVERGED_FNORM_RELATIVE - 2-norm(F) <= rtol*2-norm(F(x_0)) where x_0 is the initial guess
295 
296    Level: beginner
297 
298 .seealso: [](chapter_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`
299 M*/
300 
301 /*MC
302      SNES_CONVERGED_SNORM_RELATIVE - The 2-norm of the last step <= stol * 2-norm(x) where x is the current
303           solution and stol is the 4th argument to `SNESSetTolerances()`
304 
305      Options Database Keys:
306       -snes_stol <stol> - the step tolerance
307 
308    Level: beginner
309 
310 .seealso: [](chapter_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`
311 M*/
312 
313 /*MC
314      SNES_DIVERGED_FUNCTION_COUNT - The user provided function has been called more times then the final
315          argument to `SNESSetTolerances()`
316 
317    Level: beginner
318 
319 .seealso: [](chapter_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`
320 M*/
321 
322 /*MC
323      SNES_DIVERGED_DTOL - The norm of the function has increased by a factor of divtol set with `SNESSetDivergenceTolerance()`
324 
325    Level: beginner
326 
327 .seealso: [](chapter_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`, `SNESSetDivergenceTolerance()`
328 M*/
329 
330 /*MC
331      SNES_DIVERGED_FNORM_NAN - the 2-norm of the current function evaluation is not-a-number (NaN), this
332       is usually caused by a division of 0 by 0.
333 
334    Level: beginner
335 
336 .seealso: [](chapter_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`
337 M*/
338 
339 /*MC
340      SNES_DIVERGED_MAX_IT - SNESSolve() has reached the maximum number of iterations requested
341 
342    Level: beginner
343 
344 .seealso: [](chapter_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`
345 M*/
346 
347 /*MC
348      SNES_DIVERGED_LINE_SEARCH - The line search has failed. This only occurs for a `SNES` solvers that use a line search
349 
350    Level: beginner
351 
352 .seealso: [](chapter_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`, `SNESLineSearch`
353 M*/
354 
355 /*MC
356      SNES_DIVERGED_LOCAL_MIN - the algorithm seems to have stagnated at a local minimum that is not zero.
357         See the manual page for `SNESConvergedReason` for more details
358 
359    Level: beginner
360 
361 .seealso: [](chapter_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`
362 M*/
363 
364 /*MC
365      SNES_CONERGED_ITERATING - this only occurs if `SNESGetConvergedReason()` is called during the `SNESSolve()`
366 
367    Level: beginner
368 
369 .seealso: [](chapter_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`
370 M*/
371 
372 PETSC_EXTERN PetscErrorCode SNESSetConvergenceTest(SNES, PetscErrorCode (*)(SNES, PetscInt, PetscReal, PetscReal, PetscReal, SNESConvergedReason *, void *), void *, PetscErrorCode (*)(void *));
373 PETSC_EXTERN PetscErrorCode SNESConvergedDefault(SNES, PetscInt, PetscReal, PetscReal, PetscReal, SNESConvergedReason *, void *);
374 PETSC_EXTERN PetscErrorCode SNESConvergedSkip(SNES, PetscInt, PetscReal, PetscReal, PetscReal, SNESConvergedReason *, void *);
375 PETSC_EXTERN PetscErrorCode SNESConvergedCorrectPressure(SNES, PetscInt, PetscReal, PetscReal, PetscReal, SNESConvergedReason *, void *);
376 PETSC_EXTERN PetscErrorCode SNESGetConvergedReason(SNES, SNESConvergedReason *);
377 PETSC_EXTERN PetscErrorCode SNESGetConvergedReasonString(SNES, const char **);
378 PETSC_EXTERN PetscErrorCode SNESSetConvergedReason(SNES, SNESConvergedReason);
379 
380 PETSC_DEPRECATED_FUNCTION("Use SNESConvergedSkip() (since version 3.5)") static inline void SNESSkipConverged(void)
381 { /* never called */
382 }
383 #define SNESSkipConverged (SNESSkipConverged, SNESConvergedSkip)
384 
385 /* --------- Solving systems of nonlinear equations --------------- */
386 PETSC_EXTERN PetscErrorCode SNESSetFunction(SNES, Vec, PetscErrorCode (*)(SNES, Vec, Vec, void *), void *);
387 PETSC_EXTERN PetscErrorCode SNESGetFunction(SNES, Vec *, PetscErrorCode (**)(SNES, Vec, Vec, void *), void **);
388 PETSC_EXTERN PetscErrorCode SNESComputeFunction(SNES, Vec, Vec);
389 PETSC_EXTERN PetscErrorCode SNESComputeMFFunction(SNES, Vec, Vec);
390 PETSC_EXTERN PetscErrorCode SNESSetInitialFunction(SNES, Vec);
391 
392 PETSC_EXTERN PetscErrorCode SNESSetJacobian(SNES, Mat, Mat, PetscErrorCode (*)(SNES, Vec, Mat, Mat, void *), void *);
393 PETSC_EXTERN PetscErrorCode SNESGetJacobian(SNES, Mat *, Mat *, PetscErrorCode (**)(SNES, Vec, Mat, Mat, void *), void **);
394 PETSC_EXTERN PetscErrorCode SNESObjectiveComputeFunctionDefaultFD(SNES, Vec, Vec, void *);
395 PETSC_EXTERN PetscErrorCode SNESComputeJacobianDefault(SNES, Vec, Mat, Mat, void *);
396 PETSC_EXTERN PetscErrorCode SNESComputeJacobianDefaultColor(SNES, Vec, Mat, Mat, void *);
397 PETSC_EXTERN PetscErrorCode SNESPruneJacobianColor(SNES, Mat, Mat);
398 PETSC_EXTERN PetscErrorCode SNESSetComputeInitialGuess(SNES, PetscErrorCode (*)(SNES, Vec, void *), void *);
399 PETSC_EXTERN PetscErrorCode SNESSetPicard(SNES, Vec, PetscErrorCode (*)(SNES, Vec, Vec, void *), Mat, Mat, PetscErrorCode (*)(SNES, Vec, Mat, Mat, void *), void *);
400 PETSC_EXTERN PetscErrorCode SNESGetPicard(SNES, Vec *, PetscErrorCode (**)(SNES, Vec, Vec, void *), Mat *, Mat *, PetscErrorCode (**)(SNES, Vec, Mat, Mat, void *), void **);
401 PETSC_EXTERN PetscErrorCode SNESPicardComputeFunction(SNES, Vec, Vec, void *);
402 PETSC_EXTERN PetscErrorCode SNESPicardComputeMFFunction(SNES, Vec, Vec, void *);
403 PETSC_EXTERN PetscErrorCode SNESPicardComputeJacobian(SNES, Vec, Mat, Mat, void *);
404 
405 PETSC_EXTERN PetscErrorCode SNESSetObjective(SNES, PetscErrorCode (*)(SNES, Vec, PetscReal *, void *), void *);
406 PETSC_EXTERN PetscErrorCode SNESGetObjective(SNES, PetscErrorCode (**)(SNES, Vec, PetscReal *, void *), void **);
407 PETSC_EXTERN PetscErrorCode SNESComputeObjective(SNES, Vec, PetscReal *);
408 
409 /*E
410     SNESNormSchedule - Frequency with which the norm is computed
411 
412    Level: advanced
413 
414    Values:
415 +   `SNES_NORM_DEFAULT` - use the default behavior for the current `SNESType`
416 .   `SNES_NORM_NONE` - avoid all norm computations
417 .   `SNES_NORM_ALWAYS` - compute the norms whenever possible
418 .   `SNES_NORM_INITIAL_ONLY` - compute the norm only when the algorithm starts
419 .   `SNES_NORM_FINAL_ONLY` - compute the norm only when the algorithm finishes
420 -   `SNES_NORM_INITIAL_FINAL_ONLY` - compute the norm at the start and end of the algorithm
421 
422    Notes:
423    Support for these is highly dependent on the solver.
424 
425    Some options limit the convergence tests that can be used.
426 
427    The `SNES_NORM_NONE` option is most commonly used when the nonlinear solver is being used as a smoother, for example for `SNESFAS`
428 
429    This is primarily used to turn off extra norm and function computation
430    when the solvers are composed.
431 
432 .seealso: [](chapter_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `KSPSetNormType()`,
433           `KSPSetConvergenceTest()`, `KSPSetPCSide()`
434 E*/
435 typedef enum {
436   SNES_NORM_DEFAULT            = -1,
437   SNES_NORM_NONE               = 0,
438   SNES_NORM_ALWAYS             = 1,
439   SNES_NORM_INITIAL_ONLY       = 2,
440   SNES_NORM_FINAL_ONLY         = 3,
441   SNES_NORM_INITIAL_FINAL_ONLY = 4
442 } SNESNormSchedule;
443 PETSC_EXTERN const char *const *const SNESNormSchedules;
444 
445 /*MC
446     SNES_NORM_NONE - Don't compute function and its L2 norm.
447 
448    Level: advanced
449 
450     Note:
451     This is most useful for stationary solvers with a fixed number of iterations used as smoothers.
452 
453 .seealso: [](chapter_snes), `SNESNormSchedule`, `SNES`, `SNESSetNormSchedule()`, `SNES_NORM_DEFAULT`
454 M*/
455 
456 /*MC
457     SNES_NORM_ALWAYS - Compute the function and its L2 norm at each iteration.
458 
459    Level: advanced
460 
461     Note:
462     Most solvers will use this no matter what norm type is passed to them.
463 
464 .seealso: [](chapter_snes), `SNESNormSchedule`, `SNES`, `SNESSetNormSchedule()`, `SNES_NORM_NONE`
465 M*/
466 
467 /*MC
468     SNES_NORM_INITIAL_ONLY - Compute the function and its L2 at iteration 0, but do not update it.
469 
470    Level: advanced
471 
472    Notes:
473    This method is useful in composed methods, when a true solution might actually be found before `SNESSolve()` is called.
474    This option enables the solve to abort on the zeroth iteration if this is the case.
475 
476    For solvers that require the computation of the L2 norm of the function as part of the method, this merely cancels
477    the norm computation at the last iteration (if possible).
478 
479 .seealso: [](chapter_snes), `SNESNormSchedule`, `SNES`, `SNESSetNormSchedule()`, `SNES_NORM_FINAL_ONLY`, `SNES_NORM_INITIAL_FINAL_ONLY`
480 M*/
481 
482 /*MC
483     SNES_NORM_FINAL_ONLY - Compute the function and its L2 norm on only the final iteration.
484 
485    Level: advanced
486 
487    Note:
488    For solvers that require the computation of the L2 norm of the function as part of the method, behaves
489    exactly as `SNES_NORM_DEFAULT`.  This method is useful when the function is gotten after `SNESSolve()` and
490    used in subsequent computation for methods that do not need the norm computed during the rest of the
491    solution procedure.
492 
493 .seealso: [](chapter_snes), `SNESNormSchedule`, `SNES`, `SNESSetNormSchedule()`, `SNES_NORM_INITIAL_ONLY`, `SNES_NORM_INITIAL_FINAL_ONLY`
494 M*/
495 
496 /*MC
497     SNES_NORM_INITIAL_FINAL_ONLY - Compute the function and its L2 norm on only the initial and final iterations.
498 
499    Level: advanced
500 
501    Note:
502    This method combines the benefits of `SNES_NORM_INITIAL_ONLY` and `SNES_NORM_FINAL_ONLY`.
503 
504 .seealso: [](chapter_snes), `SNESNormSchedule`, `SNES`, `SNESSetNormSchedule()`, `SNES_NORM_SNES_NORM_INITIAL_ONLY`, `SNES_NORM_FINAL_ONLY`
505 M*/
506 
507 PETSC_EXTERN PetscErrorCode SNESSetNormSchedule(SNES, SNESNormSchedule);
508 PETSC_EXTERN PetscErrorCode SNESGetNormSchedule(SNES, SNESNormSchedule *);
509 PETSC_EXTERN PetscErrorCode SNESSetFunctionNorm(SNES, PetscReal);
510 PETSC_EXTERN PetscErrorCode SNESGetFunctionNorm(SNES, PetscReal *);
511 PETSC_EXTERN PetscErrorCode SNESGetUpdateNorm(SNES, PetscReal *);
512 PETSC_EXTERN PetscErrorCode SNESGetSolutionNorm(SNES, PetscReal *);
513 
514 /*E
515     SNESFunctionType - Type of function computed
516 
517    Level: advanced
518 
519    Values:
520 +  `SNES_FUNCTION_DEFAULT` - the default behavior for the current `SNESType`
521 .  `SNES_FUNCTION_UNPRECONDITIONED` - the original function provided
522 -  `SNES_FUNCTION_PRECONDITIONED` - the modification of the function by the preconditioner
523 
524    Note:
525    Support for these is dependent on the solver.
526 
527 .seealso: [](chapter_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `KSPSetNormType()`,
528           `KSPSetConvergenceTest()`, `KSPSetPCSide()`
529 E*/
530 typedef enum {
531   SNES_FUNCTION_DEFAULT          = -1,
532   SNES_FUNCTION_UNPRECONDITIONED = 0,
533   SNES_FUNCTION_PRECONDITIONED   = 1
534 } SNESFunctionType;
535 PETSC_EXTERN const char *const *const SNESFunctionTypes;
536 
537 PETSC_EXTERN PetscErrorCode SNESSetFunctionType(SNES, SNESFunctionType);
538 PETSC_EXTERN PetscErrorCode SNESGetFunctionType(SNES, SNESFunctionType *);
539 
540 PETSC_EXTERN PetscErrorCode SNESSetNGS(SNES, PetscErrorCode (*)(SNES, Vec, Vec, void *), void *);
541 PETSC_EXTERN PetscErrorCode SNESGetNGS(SNES, PetscErrorCode (**)(SNES, Vec, Vec, void *), void **);
542 PETSC_EXTERN PetscErrorCode SNESComputeNGS(SNES, Vec, Vec);
543 
544 PETSC_EXTERN PetscErrorCode SNESNGSSetSweeps(SNES, PetscInt);
545 PETSC_EXTERN PetscErrorCode SNESNGSGetSweeps(SNES, PetscInt *);
546 PETSC_EXTERN PetscErrorCode SNESNGSSetTolerances(SNES, PetscReal, PetscReal, PetscReal, PetscInt);
547 PETSC_EXTERN PetscErrorCode SNESNGSGetTolerances(SNES, PetscReal *, PetscReal *, PetscReal *, PetscInt *);
548 
549 PETSC_EXTERN PetscErrorCode SNESSetAlwaysComputesFinalResidual(SNES, PetscBool);
550 PETSC_EXTERN PetscErrorCode SNESGetAlwaysComputesFinalResidual(SNES, PetscBool *);
551 
552 PETSC_EXTERN PetscErrorCode SNESShellGetContext(SNES, void *);
553 PETSC_EXTERN PetscErrorCode SNESShellSetContext(SNES, void *);
554 PETSC_EXTERN PetscErrorCode SNESShellSetSolve(SNES, PetscErrorCode (*)(SNES, Vec));
555 
556 /* --------- Routines specifically for line search methods --------------- */
557 
558 /*S
559      SNESLineSearch - Abstract PETSc object that manages line-search operations for nonlinear solvers
560 
561    Level: beginner
562 
563 .seealso: [](chapter_snes), `SNESLineSearchType`, `SNESLineSearchCreate()`, `SNESLineSearchSetType()`, `SNES`
564 S*/
565 typedef struct _p_LineSearch *SNESLineSearch;
566 
567 /*J
568     SNESLineSearchType - String with the name of a PETSc line search method `SNESLineSearch`
569 
570    Level: beginner
571 
572 .seealso: [](chapter_snes), `SNESLineSearch`, `SNESLineSearchSetType()`, `SNES`
573 J*/
574 typedef const char *SNESLineSearchType;
575 #define SNESLINESEARCHBT        "bt"
576 #define SNESLINESEARCHNLEQERR   "nleqerr"
577 #define SNESLINESEARCHBASIC     "basic"
578 #define SNESLINESEARCHNONE      "none"
579 #define SNESLINESEARCHL2        "l2"
580 #define SNESLINESEARCHCP        "cp"
581 #define SNESLINESEARCHSHELL     "shell"
582 #define SNESLINESEARCHNCGLINEAR "ncglinear"
583 
584 PETSC_EXTERN PetscFunctionList SNESList;
585 PETSC_EXTERN PetscClassId      SNESLINESEARCH_CLASSID;
586 PETSC_EXTERN PetscFunctionList SNESLineSearchList;
587 
588 #define SNES_LINESEARCH_ORDER_LINEAR    1
589 #define SNES_LINESEARCH_ORDER_QUADRATIC 2
590 #define SNES_LINESEARCH_ORDER_CUBIC     3
591 
592 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode (*SNESLineSearchVIProjectFunc)(SNES, Vec);
593 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode (*SNESLineSearchVINormFunc)(SNES, Vec, Vec, PetscReal *);
594 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode (*SNESLineSearchApplyFunc)(SNESLineSearch);
595 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode (*SNESLineSearchUserFunc)(SNESLineSearch, void *);
596 
597 PETSC_EXTERN PetscErrorCode SNESLineSearchCreate(MPI_Comm, SNESLineSearch *);
598 PETSC_EXTERN PetscErrorCode SNESLineSearchReset(SNESLineSearch);
599 PETSC_EXTERN PetscErrorCode SNESLineSearchView(SNESLineSearch, PetscViewer);
600 PETSC_EXTERN PetscErrorCode SNESLineSearchDestroy(SNESLineSearch *);
601 PETSC_EXTERN PetscErrorCode SNESLineSearchGetType(SNESLineSearch, SNESLineSearchType *);
602 PETSC_EXTERN PetscErrorCode SNESLineSearchSetType(SNESLineSearch, SNESLineSearchType);
603 PETSC_EXTERN PetscErrorCode SNESLineSearchSetFromOptions(SNESLineSearch);
604 PETSC_EXTERN PetscErrorCode SNESLineSearchSetFunction(SNESLineSearch, PetscErrorCode (*)(SNES, Vec, Vec));
605 PETSC_EXTERN PetscErrorCode SNESLineSearchSetUp(SNESLineSearch);
606 PETSC_EXTERN PetscErrorCode SNESLineSearchApply(SNESLineSearch, Vec, Vec, PetscReal *, Vec);
607 PETSC_EXTERN PetscErrorCode SNESLineSearchPreCheck(SNESLineSearch, Vec, Vec, PetscBool *);
608 PETSC_EXTERN PetscErrorCode SNESLineSearchPostCheck(SNESLineSearch, Vec, Vec, Vec, PetscBool *, PetscBool *);
609 PETSC_EXTERN PetscErrorCode SNESLineSearchSetWorkVecs(SNESLineSearch, PetscInt);
610 
611 /* set the functions for precheck and postcheck */
612 
613 PETSC_EXTERN PetscErrorCode SNESLineSearchSetPreCheck(SNESLineSearch, PetscErrorCode (*)(SNESLineSearch, Vec, Vec, PetscBool *, void *), void *ctx);
614 PETSC_EXTERN PetscErrorCode SNESLineSearchSetPostCheck(SNESLineSearch, PetscErrorCode (*)(SNESLineSearch, Vec, Vec, Vec, PetscBool *, PetscBool *, void *), void *ctx);
615 
616 PETSC_EXTERN PetscErrorCode SNESLineSearchGetPreCheck(SNESLineSearch, PetscErrorCode (**)(SNESLineSearch, Vec, Vec, PetscBool *, void *), void **ctx);
617 PETSC_EXTERN PetscErrorCode SNESLineSearchGetPostCheck(SNESLineSearch, PetscErrorCode (**)(SNESLineSearch, Vec, Vec, Vec, PetscBool *, PetscBool *, void *), void **ctx);
618 
619 /* set the functions for VI-specific line search operations */
620 
621 PETSC_EXTERN PetscErrorCode SNESLineSearchSetVIFunctions(SNESLineSearch, SNESLineSearchVIProjectFunc, SNESLineSearchVINormFunc);
622 PETSC_EXTERN PetscErrorCode SNESLineSearchGetVIFunctions(SNESLineSearch, SNESLineSearchVIProjectFunc *, SNESLineSearchVINormFunc *);
623 
624 /* pointers to the associated SNES in order to be able to get the function evaluation out */
625 PETSC_EXTERN PetscErrorCode SNESLineSearchSetSNES(SNESLineSearch, SNES);
626 PETSC_EXTERN PetscErrorCode SNESLineSearchGetSNES(SNESLineSearch, SNES *);
627 
628 /* set and get the parameters and vectors */
629 PETSC_EXTERN PetscErrorCode SNESLineSearchGetTolerances(SNESLineSearch, PetscReal *, PetscReal *, PetscReal *, PetscReal *, PetscReal *, PetscInt *);
630 PETSC_EXTERN PetscErrorCode SNESLineSearchSetTolerances(SNESLineSearch, PetscReal, PetscReal, PetscReal, PetscReal, PetscReal, PetscInt);
631 
632 PETSC_EXTERN PetscErrorCode SNESLineSearchPreCheckPicard(SNESLineSearch, Vec, Vec, PetscBool *, void *);
633 
634 PETSC_EXTERN PetscErrorCode SNESLineSearchGetLambda(SNESLineSearch, PetscReal *);
635 PETSC_EXTERN PetscErrorCode SNESLineSearchSetLambda(SNESLineSearch, PetscReal);
636 
637 PETSC_EXTERN PetscErrorCode SNESLineSearchGetDamping(SNESLineSearch, PetscReal *);
638 PETSC_EXTERN PetscErrorCode SNESLineSearchSetDamping(SNESLineSearch, PetscReal);
639 
640 PETSC_EXTERN PetscErrorCode SNESLineSearchGetOrder(SNESLineSearch, PetscInt *order);
641 PETSC_EXTERN PetscErrorCode SNESLineSearchSetOrder(SNESLineSearch, PetscInt order);
642 
643 /*E
644     SNESLineSearchReason - indication if the line search has succeeded or failed and why
645 
646    Level: intermediate
647 
648   Values:
649 +  `SNES_LINESEARCH_SUCCEEDED` - the line search succeeded
650 .  `SNES_LINESEARCH_FAILED_NANORINF` - a not a number of infinity appeared in the computions
651 .  `SNES_LINESEARCH_FAILED_DOMAIN` - the function was evaluated outside of its domain, see `SNESSetFunctionDomainError()` and `SNESSetJacobianDomainError()`
652 .  `SNES_LINESEARCH_FAILED_REDUCT` - the linear search failed to get the requested decrease in its norm or objective
653 .  `SNES_LINESEARCH_FAILED_USER` - used by `SNESLINESEARCHNLEQERR` to indicate the user changed the search direction inappropriately
654 -  `SNES_LINESEARCH_FAILED_FUNCTION` - indicates the maximum number of function evaluations allowed has been surpassed, `SNESConvergedReason` is also
655                                      set to `SNES_DIVERGED_FUNCTION_COUNT`
656 
657    Developer Note:
658    Some of these reasons overlap with values of `SNESConvergedReason`
659 
660 .seealso: [](chapter_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `KSPConvergedReason`, `SNESSetConvergenceTest()`,
661           `SNESSetFunctionDomainError()` and `SNESSetJacobianDomainError()`
662 E*/
663 typedef enum {
664   SNES_LINESEARCH_SUCCEEDED,
665   SNES_LINESEARCH_FAILED_NANORINF,
666   SNES_LINESEARCH_FAILED_DOMAIN,
667   SNES_LINESEARCH_FAILED_REDUCT, /* INSUFFICIENT REDUCTION */
668   SNES_LINESEARCH_FAILED_USER,
669   SNES_LINESEARCH_FAILED_FUNCTION
670 } SNESLineSearchReason;
671 
672 PETSC_EXTERN PetscErrorCode SNESLineSearchGetReason(SNESLineSearch, SNESLineSearchReason *);
673 PETSC_EXTERN PetscErrorCode SNESLineSearchSetReason(SNESLineSearch, SNESLineSearchReason);
674 
675 PETSC_EXTERN PetscErrorCode SNESLineSearchGetVecs(SNESLineSearch, Vec *, Vec *, Vec *, Vec *, Vec *);
676 PETSC_EXTERN PetscErrorCode SNESLineSearchSetVecs(SNESLineSearch, Vec, Vec, Vec, Vec, Vec);
677 
678 PETSC_EXTERN PetscErrorCode SNESLineSearchGetNorms(SNESLineSearch, PetscReal *, PetscReal *, PetscReal *);
679 PETSC_EXTERN PetscErrorCode SNESLineSearchSetNorms(SNESLineSearch, PetscReal, PetscReal, PetscReal);
680 PETSC_EXTERN PetscErrorCode SNESLineSearchComputeNorms(SNESLineSearch);
681 PETSC_EXTERN PetscErrorCode SNESLineSearchSetComputeNorms(SNESLineSearch, PetscBool);
682 
683 PETSC_EXTERN PetscErrorCode SNESLineSearchMonitor(SNESLineSearch);
684 PETSC_EXTERN PetscErrorCode SNESLineSearchMonitorSet(SNESLineSearch, PetscErrorCode (*)(SNESLineSearch, void *), void *, PetscErrorCode (*)(void **));
685 PETSC_EXTERN PetscErrorCode SNESLineSearchMonitorSetFromOptions(SNESLineSearch, const char[], const char[], const char[], PetscErrorCode (*)(SNESLineSearch, PetscViewerAndFormat *), PetscErrorCode (*)(SNESLineSearch, PetscViewerAndFormat *));
686 PETSC_EXTERN PetscErrorCode SNESLineSearchMonitorCancel(SNESLineSearch);
687 PETSC_EXTERN PetscErrorCode SNESLineSearchMonitorUpdate(SNESLineSearch, PetscViewerAndFormat *);
688 PETSC_EXTERN PetscErrorCode SNESLineSearchSetDefaultMonitor(SNESLineSearch, PetscViewer);
689 PETSC_EXTERN PetscErrorCode SNESLineSearchGetDefaultMonitor(SNESLineSearch, PetscViewer *);
690 PETSC_EXTERN PetscErrorCode SNESLineSearchMonitorSolutionUpdate(SNESLineSearch, PetscViewerAndFormat *);
691 
692 PETSC_EXTERN PetscErrorCode SNESLineSearchAppendOptionsPrefix(SNESLineSearch, const char prefix[]);
693 PETSC_EXTERN PetscErrorCode SNESLineSearchGetOptionsPrefix(SNESLineSearch, const char *prefix[]);
694 
695 /* Shell interface functions */
696 PETSC_EXTERN PetscErrorCode SNESLineSearchShellSetUserFunc(SNESLineSearch, SNESLineSearchUserFunc, void *);
697 PETSC_EXTERN PetscErrorCode SNESLineSearchShellGetUserFunc(SNESLineSearch, SNESLineSearchUserFunc *, void **);
698 
699 /* BT interface functions */
700 PETSC_EXTERN PetscErrorCode SNESLineSearchBTSetAlpha(SNESLineSearch, PetscReal);
701 PETSC_EXTERN PetscErrorCode SNESLineSearchBTGetAlpha(SNESLineSearch, PetscReal *);
702 
703 /*register line search types */
704 PETSC_EXTERN PetscErrorCode SNESLineSearchRegister(const char[], PetscErrorCode (*)(SNESLineSearch));
705 
706 /* Routines for VI solver */
707 PETSC_EXTERN PetscErrorCode SNESVISetVariableBounds(SNES, Vec, Vec);
708 PETSC_EXTERN PetscErrorCode SNESVIGetVariableBounds(SNES, Vec *, Vec *);
709 PETSC_EXTERN PetscErrorCode SNESVISetComputeVariableBounds(SNES, PetscErrorCode (*)(SNES, Vec, Vec));
710 PETSC_EXTERN PetscErrorCode SNESVIGetInactiveSet(SNES, IS *);
711 PETSC_EXTERN PetscErrorCode SNESVIGetActiveSetIS(SNES, Vec, Vec, IS *);
712 PETSC_EXTERN PetscErrorCode SNESVIComputeInactiveSetFnorm(SNES, Vec, Vec, PetscReal *);
713 PETSC_EXTERN PetscErrorCode SNESVISetRedundancyCheck(SNES, PetscErrorCode (*)(SNES, IS, IS *, void *), void *);
714 PETSC_EXTERN PetscErrorCode SNESVIComputeMeritFunction(Vec, PetscReal *, PetscReal *);
715 PETSC_EXTERN PetscErrorCode SNESVIComputeFunction(SNES, Vec, Vec, void *);
716 PETSC_EXTERN PetscErrorCode DMSetVI(DM, IS);
717 PETSC_EXTERN PetscErrorCode DMDestroyVI(DM);
718 
719 PETSC_EXTERN PetscErrorCode SNESTestLocalMin(SNES);
720 
721 /* Should this routine be private? */
722 PETSC_EXTERN PetscErrorCode SNESComputeJacobian(SNES, Vec, Mat, Mat);
723 PETSC_EXTERN PetscErrorCode SNESTestJacobian(SNES);
724 
725 PETSC_EXTERN PetscErrorCode SNESSetDM(SNES, DM);
726 PETSC_EXTERN PetscErrorCode SNESGetDM(SNES, DM *);
727 PETSC_EXTERN PetscErrorCode SNESSetNPC(SNES, SNES);
728 PETSC_EXTERN PetscErrorCode SNESGetNPC(SNES, SNES *);
729 PETSC_EXTERN PetscErrorCode SNESHasNPC(SNES, PetscBool *);
730 PETSC_EXTERN PetscErrorCode SNESApplyNPC(SNES, Vec, Vec, Vec);
731 PETSC_EXTERN PetscErrorCode SNESGetNPCFunction(SNES, Vec, PetscReal *);
732 PETSC_EXTERN PetscErrorCode SNESComputeFunctionDefaultNPC(SNES, Vec, Vec);
733 PETSC_EXTERN PetscErrorCode SNESSetNPCSide(SNES, PCSide);
734 PETSC_EXTERN PetscErrorCode SNESGetNPCSide(SNES, PCSide *);
735 PETSC_EXTERN PetscErrorCode SNESSetLineSearch(SNES, SNESLineSearch);
736 PETSC_EXTERN PetscErrorCode SNESGetLineSearch(SNES, SNESLineSearch *);
737 PETSC_EXTERN PetscErrorCode SNESRestrictHookAdd(SNES, PetscErrorCode (*)(SNES, SNES, void *), void *);
738 
739 PETSC_DEPRECATED_FUNCTION("Use SNESGetLineSearch() (since version 3.4)") static inline PetscErrorCode SNESGetSNESLineSearch(SNES snes, SNESLineSearch *ls)
740 {
741   return SNESGetLineSearch(snes, ls);
742 }
743 PETSC_DEPRECATED_FUNCTION("Use SNESSetLineSearch() (since version 3.4)") static inline PetscErrorCode SNESSetSNESLineSearch(SNES snes, SNESLineSearch ls)
744 {
745   return SNESSetLineSearch(snes, ls);
746 }
747 
748 PETSC_EXTERN PetscErrorCode SNESSetUpMatrices(SNES);
749 PETSC_EXTERN PetscErrorCode DMSNESSetFunction(DM, PetscErrorCode (*)(SNES, Vec, Vec, void *), void *);
750 PETSC_EXTERN PetscErrorCode DMSNESGetFunction(DM, PetscErrorCode (**)(SNES, Vec, Vec, void *), void **);
751 PETSC_EXTERN PetscErrorCode DMSNESSetFunctionContextDestroy(DM, PetscErrorCode (*)(void *));
752 PETSC_EXTERN PetscErrorCode DMSNESSetMFFunction(DM, PetscErrorCode (*)(SNES, Vec, Vec, void *), void *);
753 PETSC_EXTERN PetscErrorCode DMSNESSetNGS(DM, PetscErrorCode (*)(SNES, Vec, Vec, void *), void *);
754 PETSC_EXTERN PetscErrorCode DMSNESGetNGS(DM, PetscErrorCode (**)(SNES, Vec, Vec, void *), void **);
755 PETSC_EXTERN PetscErrorCode DMSNESSetJacobian(DM, PetscErrorCode (*)(SNES, Vec, Mat, Mat, void *), void *);
756 PETSC_EXTERN PetscErrorCode DMSNESGetJacobian(DM, PetscErrorCode (**)(SNES, Vec, Mat, Mat, void *), void **);
757 PETSC_EXTERN PetscErrorCode DMSNESSetJacobianContextDestroy(DM, PetscErrorCode (*)(void *));
758 PETSC_EXTERN PetscErrorCode DMSNESSetPicard(DM, PetscErrorCode (*)(SNES, Vec, Vec, void *), PetscErrorCode (*)(SNES, Vec, Mat, Mat, void *), void *);
759 PETSC_EXTERN PetscErrorCode DMSNESGetPicard(DM, PetscErrorCode (**)(SNES, Vec, Vec, void *), PetscErrorCode (**)(SNES, Vec, Mat, Mat, void *), void **);
760 PETSC_EXTERN PetscErrorCode DMSNESSetObjective(DM, PetscErrorCode (*)(SNES, Vec, PetscReal *, void *), void *);
761 PETSC_EXTERN PetscErrorCode DMSNESGetObjective(DM, PetscErrorCode (**)(SNES, Vec, PetscReal *, void *), void **);
762 PETSC_EXTERN PetscErrorCode DMCopyDMSNES(DM, DM);
763 
764 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode (*DMDASNESFunction)(DMDALocalInfo *, void *, void *, void *);
765 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode (*DMDASNESJacobian)(DMDALocalInfo *, void *, Mat, Mat, void *);
766 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode (*DMDASNESObjective)(DMDALocalInfo *, void *, PetscReal *, void *);
767 
768 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode (*DMDASNESFunctionVec)(DMDALocalInfo *, Vec, Vec, void *);
769 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode (*DMDASNESJacobianVec)(DMDALocalInfo *, Vec, Mat, Mat, void *);
770 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode (*DMDASNESObjectiveVec)(DMDALocalInfo *, Vec, PetscReal *, void *);
771 
772 PETSC_EXTERN PetscErrorCode DMDASNESSetFunctionLocal(DM, InsertMode, DMDASNESFunction, void *);
773 PETSC_EXTERN PetscErrorCode DMDASNESSetJacobianLocal(DM, DMDASNESJacobian, void *);
774 PETSC_EXTERN PetscErrorCode DMDASNESSetObjectiveLocal(DM, DMDASNESObjective, void *);
775 PETSC_EXTERN PetscErrorCode DMDASNESSetPicardLocal(DM, InsertMode, PetscErrorCode (*)(DMDALocalInfo *, void *, void *, void *), PetscErrorCode (*)(DMDALocalInfo *, void *, Mat, Mat, void *), void *);
776 
777 PETSC_EXTERN PetscErrorCode DMDASNESSetFunctionLocalVec(DM, InsertMode, DMDASNESFunctionVec, void *);
778 PETSC_EXTERN PetscErrorCode DMDASNESSetJacobianLocalVec(DM, DMDASNESJacobianVec, void *);
779 PETSC_EXTERN PetscErrorCode DMDASNESSetObjectiveLocalVec(DM, DMDASNESObjectiveVec, void *);
780 
781 PETSC_EXTERN PetscErrorCode DMSNESSetBoundaryLocal(DM, PetscErrorCode (*)(DM, Vec, void *), void *);
782 PETSC_EXTERN PetscErrorCode DMSNESSetFunctionLocal(DM, PetscErrorCode (*)(DM, Vec, Vec, void *), void *);
783 PETSC_EXTERN PetscErrorCode DMSNESSetJacobianLocal(DM, PetscErrorCode (*)(DM, Vec, Mat, Mat, void *), void *);
784 PETSC_EXTERN PetscErrorCode DMSNESGetBoundaryLocal(DM, PetscErrorCode (**)(DM, Vec, void *), void **);
785 PETSC_EXTERN PetscErrorCode DMSNESGetFunctionLocal(DM, PetscErrorCode (**)(DM, Vec, Vec, void *), void **);
786 PETSC_EXTERN PetscErrorCode DMSNESGetJacobianLocal(DM, PetscErrorCode (**)(DM, Vec, Mat, Mat, void *), void **);
787 
788 /* Routines for Multiblock solver */
789 PETSC_EXTERN PetscErrorCode SNESMultiblockSetFields(SNES, const char[], PetscInt, const PetscInt *);
790 PETSC_EXTERN PetscErrorCode SNESMultiblockSetIS(SNES, const char[], IS);
791 PETSC_EXTERN PetscErrorCode SNESMultiblockSetBlockSize(SNES, PetscInt);
792 PETSC_EXTERN PetscErrorCode SNESMultiblockSetType(SNES, PCCompositeType);
793 
794 /*J
795     SNESMSType - String with the name of a PETSc `SNESMS` method.
796 
797    Level: intermediate
798 
799 .seealso: [](chapter_snes), `SNESMS`, `SNESMSGetType()`, `SNESMSSetType()`, `SNES`
800 J*/
801 typedef const char *SNESMSType;
802 #define SNESMSM62       "m62"
803 #define SNESMSEULER     "euler"
804 #define SNESMSJAMESON83 "jameson83"
805 #define SNESMSVLTP11    "vltp11"
806 #define SNESMSVLTP21    "vltp21"
807 #define SNESMSVLTP31    "vltp31"
808 #define SNESMSVLTP41    "vltp41"
809 #define SNESMSVLTP51    "vltp51"
810 #define SNESMSVLTP61    "vltp61"
811 
812 PETSC_EXTERN PetscErrorCode SNESMSRegister(SNESMSType, PetscInt, PetscInt, PetscReal, const PetscReal[], const PetscReal[], const PetscReal[]);
813 PETSC_EXTERN PetscErrorCode SNESMSGetType(SNES, SNESMSType *);
814 PETSC_EXTERN PetscErrorCode SNESMSSetType(SNES, SNESMSType);
815 PETSC_EXTERN PetscErrorCode SNESMSGetDamping(SNES, PetscReal *);
816 PETSC_EXTERN PetscErrorCode SNESMSSetDamping(SNES, PetscReal);
817 PETSC_EXTERN PetscErrorCode SNESMSFinalizePackage(void);
818 PETSC_EXTERN PetscErrorCode SNESMSInitializePackage(void);
819 PETSC_EXTERN PetscErrorCode SNESMSRegisterDestroy(void);
820 
821 /* routines for NGMRES solver */
822 
823 typedef enum {
824   SNES_NGMRES_RESTART_NONE       = 0,
825   SNES_NGMRES_RESTART_PERIODIC   = 1,
826   SNES_NGMRES_RESTART_DIFFERENCE = 2
827 } SNESNGMRESRestartType;
828 PETSC_EXTERN const char *const SNESNGMRESRestartTypes[];
829 
830 typedef enum {
831   SNES_NGMRES_SELECT_NONE       = 0,
832   SNES_NGMRES_SELECT_DIFFERENCE = 1,
833   SNES_NGMRES_SELECT_LINESEARCH = 2
834 } SNESNGMRESSelectType;
835 PETSC_EXTERN const char *const SNESNGMRESSelectTypes[];
836 
837 PETSC_EXTERN PetscErrorCode SNESNGMRESSetRestartType(SNES, SNESNGMRESRestartType);
838 PETSC_EXTERN PetscErrorCode SNESNGMRESSetSelectType(SNES, SNESNGMRESSelectType);
839 PETSC_EXTERN PetscErrorCode SNESNGMRESSetRestartFmRise(SNES, PetscBool);
840 PETSC_EXTERN PetscErrorCode SNESNGMRESGetRestartFmRise(SNES, PetscBool *);
841 
842 /* routines for NCG solver */
843 
844 typedef enum {
845   SNES_NCG_FR  = 0,
846   SNES_NCG_PRP = 1,
847   SNES_NCG_HS  = 2,
848   SNES_NCG_DY  = 3,
849   SNES_NCG_CD  = 4
850 } SNESNCGType;
851 PETSC_EXTERN const char *const SNESNCGTypes[];
852 
853 PETSC_EXTERN PetscErrorCode SNESNCGSetType(SNES, SNESNCGType);
854 
855 typedef enum {
856   SNES_QN_SCALE_DEFAULT  = 0,
857   SNES_QN_SCALE_NONE     = 1,
858   SNES_QN_SCALE_SCALAR   = 2,
859   SNES_QN_SCALE_DIAGONAL = 3,
860   SNES_QN_SCALE_JACOBIAN = 4
861 } SNESQNScaleType;
862 PETSC_EXTERN const char *const SNESQNScaleTypes[];
863 typedef enum {
864   SNES_QN_RESTART_DEFAULT  = 0,
865   SNES_QN_RESTART_NONE     = 1,
866   SNES_QN_RESTART_POWELL   = 2,
867   SNES_QN_RESTART_PERIODIC = 3
868 } SNESQNRestartType;
869 PETSC_EXTERN const char *const SNESQNRestartTypes[];
870 typedef enum {
871   SNES_QN_LBFGS      = 0,
872   SNES_QN_BROYDEN    = 1,
873   SNES_QN_BADBROYDEN = 2
874 } SNESQNType;
875 PETSC_EXTERN const char *const SNESQNTypes[];
876 
877 PETSC_EXTERN PetscErrorCode SNESQNSetType(SNES, SNESQNType);
878 PETSC_EXTERN PetscErrorCode SNESQNSetScaleType(SNES, SNESQNScaleType);
879 PETSC_EXTERN PetscErrorCode SNESQNSetRestartType(SNES, SNESQNRestartType);
880 
881 PETSC_EXTERN PetscErrorCode SNESNASMGetType(SNES, PCASMType *);
882 PETSC_EXTERN PetscErrorCode SNESNASMSetType(SNES, PCASMType);
883 PETSC_EXTERN PetscErrorCode SNESNASMGetSubdomains(SNES, PetscInt *, SNES **, VecScatter **, VecScatter **, VecScatter **);
884 PETSC_EXTERN PetscErrorCode SNESNASMSetSubdomains(SNES, PetscInt, SNES *, VecScatter *, VecScatter *, VecScatter *);
885 PETSC_EXTERN PetscErrorCode SNESNASMSetDamping(SNES, PetscReal);
886 PETSC_EXTERN PetscErrorCode SNESNASMGetDamping(SNES, PetscReal *);
887 PETSC_EXTERN PetscErrorCode SNESNASMGetSubdomainVecs(SNES, PetscInt *, Vec **, Vec **, Vec **, Vec **);
888 PETSC_EXTERN PetscErrorCode SNESNASMSetComputeFinalJacobian(SNES, PetscBool);
889 PETSC_EXTERN PetscErrorCode SNESNASMGetSNES(SNES, PetscInt, SNES *);
890 PETSC_EXTERN PetscErrorCode SNESNASMGetNumber(SNES, PetscInt *);
891 PETSC_EXTERN PetscErrorCode SNESNASMSetWeight(SNES, Vec);
892 
893 typedef enum {
894   SNES_COMPOSITE_ADDITIVE,
895   SNES_COMPOSITE_MULTIPLICATIVE,
896   SNES_COMPOSITE_ADDITIVEOPTIMAL
897 } SNESCompositeType;
898 PETSC_EXTERN const char *const SNESCompositeTypes[];
899 
900 PETSC_EXTERN PetscErrorCode SNESCompositeSetType(SNES, SNESCompositeType);
901 PETSC_EXTERN PetscErrorCode SNESCompositeAddSNES(SNES, SNESType);
902 PETSC_EXTERN PetscErrorCode SNESCompositeGetSNES(SNES, PetscInt, SNES *);
903 PETSC_EXTERN PetscErrorCode SNESCompositeGetNumber(SNES, PetscInt *);
904 PETSC_EXTERN PetscErrorCode SNESCompositeSetDamping(SNES, PetscInt, PetscReal);
905 
906 PETSC_EXTERN PetscErrorCode SNESPatchSetDiscretisationInfo(SNES, PetscInt, DM *, PetscInt *, PetscInt *, const PetscInt **, const PetscInt *, PetscInt, const PetscInt *, PetscInt, const PetscInt *);
907 PETSC_EXTERN PetscErrorCode SNESPatchSetComputeOperator(SNES, PetscErrorCode (*func)(PC, PetscInt, Vec, Mat, IS, PetscInt, const PetscInt *, const PetscInt *, void *), void *);
908 PETSC_EXTERN PetscErrorCode SNESPatchSetComputeFunction(SNES, PetscErrorCode (*func)(PC, PetscInt, Vec, Vec, IS, PetscInt, const PetscInt *, const PetscInt *, void *), void *);
909 PETSC_EXTERN PetscErrorCode SNESPatchSetConstructType(SNES, PCPatchConstructType, PetscErrorCode (*func)(PC, PetscInt *, IS **, IS *, void *), void *);
910 PETSC_EXTERN PetscErrorCode SNESPatchSetCellNumbering(SNES, PetscSection);
911 
912 /*E
913     SNESFASType - Determines the type of nonlinear multigrid method that is run.
914 
915    Level: beginner
916 
917    Values:
918 +  `SNES_FAS_MULTIPLICATIVE` (default) - traditional V or W cycle as determined by `SNESFASSetCycles()`
919 .  `SNES_FAS_ADDITIVE`                 - additive FAS cycle
920 .  `SNES_FAS_FULL`                     - full FAS cycle
921 -  `SNES_FAS_KASKADE`                  - Kaskade FAS cycle
922 
923 .seealso: [](chapter_snes), `SNESFAS`, `PCMGSetType()`, `PCMGType`
924 E*/
925 typedef enum {
926   SNES_FAS_MULTIPLICATIVE,
927   SNES_FAS_ADDITIVE,
928   SNES_FAS_FULL,
929   SNES_FAS_KASKADE
930 } SNESFASType;
931 PETSC_EXTERN const char *const SNESFASTypes[];
932 
933 /* called on the finest level FAS instance*/
934 PETSC_EXTERN PetscErrorCode SNESFASSetType(SNES, SNESFASType);
935 PETSC_EXTERN PetscErrorCode SNESFASGetType(SNES, SNESFASType *);
936 PETSC_EXTERN PetscErrorCode SNESFASSetLevels(SNES, PetscInt, MPI_Comm *);
937 PETSC_EXTERN PetscErrorCode SNESFASGetLevels(SNES, PetscInt *);
938 PETSC_EXTERN PetscErrorCode SNESFASGetCycleSNES(SNES, PetscInt, SNES *);
939 PETSC_EXTERN PetscErrorCode SNESFASSetNumberSmoothUp(SNES, PetscInt);
940 PETSC_EXTERN PetscErrorCode SNESFASSetNumberSmoothDown(SNES, PetscInt);
941 PETSC_EXTERN PetscErrorCode SNESFASSetCycles(SNES, PetscInt);
942 PETSC_EXTERN PetscErrorCode SNESFASSetMonitor(SNES, PetscViewerAndFormat *, PetscBool);
943 PETSC_EXTERN PetscErrorCode SNESFASSetLog(SNES, PetscBool);
944 
945 PETSC_EXTERN PetscErrorCode SNESFASSetGalerkin(SNES, PetscBool);
946 PETSC_EXTERN PetscErrorCode SNESFASGetGalerkin(SNES, PetscBool *);
947 PETSC_EXTERN PetscErrorCode SNESFASGalerkinFunctionDefault(SNES, Vec, Vec, void *);
948 
949 /* called on any level -- "Cycle" FAS instance */
950 PETSC_EXTERN PetscErrorCode SNESFASCycleGetSmoother(SNES, SNES *);
951 PETSC_EXTERN PetscErrorCode SNESFASCycleGetSmootherUp(SNES, SNES *);
952 PETSC_EXTERN PetscErrorCode SNESFASCycleGetSmootherDown(SNES, SNES *);
953 PETSC_EXTERN PetscErrorCode SNESFASCycleGetCorrection(SNES, SNES *);
954 PETSC_EXTERN PetscErrorCode SNESFASCycleGetInterpolation(SNES, Mat *);
955 PETSC_EXTERN PetscErrorCode SNESFASCycleGetRestriction(SNES, Mat *);
956 PETSC_EXTERN PetscErrorCode SNESFASCycleGetInjection(SNES, Mat *);
957 PETSC_EXTERN PetscErrorCode SNESFASCycleGetRScale(SNES, Vec *);
958 PETSC_EXTERN PetscErrorCode SNESFASCycleSetCycles(SNES, PetscInt);
959 PETSC_EXTERN PetscErrorCode SNESFASCycleIsFine(SNES, PetscBool *);
960 
961 /* called on the (outer) finest level FAS to set/get parameters on any level instance */
962 PETSC_EXTERN PetscErrorCode SNESFASSetInterpolation(SNES, PetscInt, Mat);
963 PETSC_EXTERN PetscErrorCode SNESFASGetInterpolation(SNES, PetscInt, Mat *);
964 PETSC_EXTERN PetscErrorCode SNESFASSetRestriction(SNES, PetscInt, Mat);
965 PETSC_EXTERN PetscErrorCode SNESFASGetRestriction(SNES, PetscInt, Mat *);
966 PETSC_EXTERN PetscErrorCode SNESFASSetInjection(SNES, PetscInt, Mat);
967 PETSC_EXTERN PetscErrorCode SNESFASGetInjection(SNES, PetscInt, Mat *);
968 PETSC_EXTERN PetscErrorCode SNESFASSetRScale(SNES, PetscInt, Vec);
969 PETSC_EXTERN PetscErrorCode SNESFASGetRScale(SNES, PetscInt, Vec *);
970 PETSC_EXTERN PetscErrorCode SNESFASSetContinuation(SNES, PetscBool);
971 
972 PETSC_EXTERN PetscErrorCode SNESFASGetSmoother(SNES, PetscInt, SNES *);
973 PETSC_EXTERN PetscErrorCode SNESFASGetSmootherUp(SNES, PetscInt, SNES *);
974 PETSC_EXTERN PetscErrorCode SNESFASGetSmootherDown(SNES, PetscInt, SNES *);
975 PETSC_EXTERN PetscErrorCode SNESFASGetCoarseSolve(SNES, SNES *);
976 
977 /* parameters for full FAS */
978 PETSC_EXTERN PetscErrorCode SNESFASFullSetDownSweep(SNES, PetscBool);
979 PETSC_EXTERN PetscErrorCode SNESFASCreateCoarseVec(SNES, Vec *);
980 PETSC_EXTERN PetscErrorCode SNESFASRestrict(SNES, Vec, Vec);
981 PETSC_EXTERN PetscErrorCode SNESFASFullSetTotal(SNES, PetscBool);
982 PETSC_EXTERN PetscErrorCode SNESFASFullGetTotal(SNES, PetscBool *);
983 
984 PETSC_EXTERN PetscErrorCode DMSNESCheckDiscretization(SNES, DM, PetscReal, Vec, PetscReal, PetscReal[]);
985 PETSC_EXTERN PetscErrorCode DMSNESCheckResidual(SNES, DM, Vec, PetscReal, PetscReal *);
986 PETSC_EXTERN PetscErrorCode DMSNESCheckJacobian(SNES, DM, Vec, PetscReal, PetscBool *, PetscReal *);
987 PETSC_EXTERN PetscErrorCode DMSNESCheckFromOptions(SNES, Vec);
988 PETSC_EXTERN PetscErrorCode DMSNESComputeJacobianAction(DM, Vec, Vec, Vec, void *);
989 PETSC_EXTERN PetscErrorCode DMSNESCreateJacobianMF(DM, Vec, void *, Mat *);
990 
991 #endif
992