xref: /petsc/include/petscsnes.h (revision 5d7a6ebe9dde080aedbe86be0085708de8f97bb7)
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 nonlinear solves
16 
17    Level: beginner
18 
19 .seealso: [](doc_nonlinsolve), [](ch_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: [](doc_nonlinsolve), [](ch_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 PETSC_EXTERN PetscErrorCode SNESFinalizePackage(void);
59 
60 PETSC_EXTERN PetscErrorCode SNESCreate(MPI_Comm, SNES *);
61 PETSC_EXTERN PetscErrorCode SNESReset(SNES);
62 PETSC_EXTERN PetscErrorCode SNESDestroy(SNES *);
63 PETSC_EXTERN PetscErrorCode SNESSetType(SNES, SNESType);
64 PETSC_EXTERN PetscErrorCode SNESMonitor(SNES, PetscInt, PetscReal);
65 PETSC_EXTERN PetscErrorCode SNESMonitorSet(SNES, PetscErrorCode (*)(SNES, PetscInt, PetscReal, void *), void *, PetscErrorCode (*)(void **));
66 PETSC_EXTERN PetscErrorCode SNESMonitorSetFromOptions(SNES, const char[], const char[], const char[], PetscErrorCode (*)(SNES, PetscInt, PetscReal, PetscViewerAndFormat *), PetscErrorCode (*)(SNES, PetscViewerAndFormat *));
67 PETSC_EXTERN PetscErrorCode SNESMonitorCancel(SNES);
68 PETSC_EXTERN PetscErrorCode SNESMonitorSAWs(SNES, PetscInt, PetscReal, void *);
69 PETSC_EXTERN PetscErrorCode SNESMonitorSAWsCreate(SNES, void **);
70 PETSC_EXTERN PetscErrorCode SNESMonitorSAWsDestroy(void **);
71 PETSC_EXTERN PetscErrorCode SNESSetConvergenceHistory(SNES, PetscReal[], PetscInt[], PetscInt, PetscBool);
72 PETSC_EXTERN PetscErrorCode SNESGetConvergenceHistory(SNES, PetscReal *[], PetscInt *[], PetscInt *);
73 PETSC_EXTERN PetscErrorCode SNESSetUp(SNES);
74 PETSC_EXTERN PetscErrorCode SNESSolve(SNES, Vec, Vec);
75 PETSC_EXTERN PetscErrorCode SNESSetErrorIfNotConverged(SNES, PetscBool);
76 PETSC_EXTERN PetscErrorCode SNESGetErrorIfNotConverged(SNES, PetscBool *);
77 PETSC_EXTERN PetscErrorCode SNESConverged(SNES, PetscInt, PetscReal, PetscReal, PetscReal);
78 
79 PETSC_EXTERN PetscErrorCode SNESSetWorkVecs(SNES, PetscInt);
80 
81 PETSC_EXTERN PetscErrorCode SNESAddOptionsChecker(PetscErrorCode (*)(SNES));
82 
83 PETSC_EXTERN PetscErrorCode SNESSetUpdate(SNES, PetscErrorCode (*)(SNES, PetscInt));
84 
85 PETSC_EXTERN PetscErrorCode SNESRegister(const char[], PetscErrorCode (*)(SNES));
86 
87 PETSC_EXTERN PetscErrorCode SNESGetKSP(SNES, KSP *);
88 PETSC_EXTERN PetscErrorCode SNESSetKSP(SNES, KSP);
89 PETSC_EXTERN PetscErrorCode SNESSetSolution(SNES, Vec);
90 PETSC_EXTERN PetscErrorCode SNESGetSolution(SNES, Vec *);
91 PETSC_EXTERN PetscErrorCode SNESGetSolutionUpdate(SNES, Vec *);
92 PETSC_EXTERN PetscErrorCode SNESGetRhs(SNES, Vec *);
93 PETSC_EXTERN PetscErrorCode SNESView(SNES, PetscViewer);
94 PETSC_EXTERN PetscErrorCode SNESLoad(SNES, PetscViewer);
95 PETSC_EXTERN PetscErrorCode SNESConvergedReasonViewSet(SNES, PetscErrorCode (*)(SNES, void *), void *, PetscErrorCode (*)(void **));
96 PETSC_EXTERN PetscErrorCode SNESViewFromOptions(SNES, PetscObject, const char[]);
97 PETSC_EXTERN PetscErrorCode SNESConvergedReasonView(SNES, PetscViewer);
98 PETSC_EXTERN PetscErrorCode SNESConvergedReasonViewFromOptions(SNES);
99 PETSC_EXTERN PetscErrorCode SNESConvergedReasonViewCancel(SNES);
100 
101 PETSC_DEPRECATED_FUNCTION(3, 14, 0, "SNESConvergedReasonView()", ) static inline PetscErrorCode SNESReasonView(SNES snes, PetscViewer v)
102 {
103   return SNESConvergedReasonView(snes, v);
104 }
105 PETSC_DEPRECATED_FUNCTION(3, 14, 0, "SNESConvergedReasonViewFromOptions()", ) static inline PetscErrorCode SNESReasonViewFromOptions(SNES snes)
106 {
107   return SNESConvergedReasonViewFromOptions(snes);
108 }
109 
110 #define SNES_FILE_CLASSID 1211224
111 
112 PETSC_EXTERN PetscErrorCode SNESSetOptionsPrefix(SNES, const char[]);
113 PETSC_EXTERN PetscErrorCode SNESAppendOptionsPrefix(SNES, const char[]);
114 PETSC_EXTERN PetscErrorCode SNESGetOptionsPrefix(SNES, const char *[]);
115 PETSC_EXTERN PetscErrorCode SNESSetFromOptions(SNES);
116 PETSC_EXTERN PetscErrorCode SNESResetFromOptions(SNES);
117 
118 PETSC_EXTERN PetscErrorCode SNESSetUseMatrixFree(SNES, PetscBool, PetscBool);
119 PETSC_EXTERN PetscErrorCode SNESGetUseMatrixFree(SNES, PetscBool *, PetscBool *);
120 PETSC_EXTERN PetscErrorCode MatCreateSNESMF(SNES, Mat *);
121 PETSC_EXTERN PetscErrorCode MatSNESMFGetSNES(Mat, SNES *);
122 PETSC_EXTERN PetscErrorCode MatSNESMFSetReuseBase(Mat, PetscBool);
123 PETSC_EXTERN PetscErrorCode MatSNESMFGetReuseBase(Mat, PetscBool *);
124 PETSC_EXTERN PetscErrorCode MatMFFDComputeJacobian(SNES, Vec, Mat, Mat, void *);
125 PETSC_EXTERN PetscErrorCode MatCreateSNESMFMore(SNES, Vec, Mat *);
126 PETSC_EXTERN PetscErrorCode MatSNESMFMoreSetParameters(Mat, PetscReal, PetscReal, PetscReal);
127 
128 PETSC_EXTERN PetscErrorCode SNESGetType(SNES, SNESType *);
129 PETSC_EXTERN PetscErrorCode SNESMonitorDefaultSetUp(SNES, PetscViewerAndFormat *);
130 PETSC_EXTERN PetscErrorCode SNESMonitorDefault(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
131 PETSC_EXTERN PetscErrorCode SNESMonitorScaling(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
132 PETSC_EXTERN PetscErrorCode SNESMonitorRange(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
133 PETSC_EXTERN PetscErrorCode SNESMonitorRatio(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
134 PETSC_EXTERN PetscErrorCode SNESMonitorRatioSetUp(SNES, PetscViewerAndFormat *);
135 PETSC_EXTERN PetscErrorCode SNESMonitorSolution(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
136 PETSC_EXTERN PetscErrorCode SNESMonitorResidual(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
137 PETSC_EXTERN PetscErrorCode SNESMonitorSolutionUpdate(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
138 PETSC_EXTERN PetscErrorCode SNESMonitorDefaultShort(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
139 PETSC_EXTERN PetscErrorCode SNESMonitorDefaultField(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
140 PETSC_EXTERN PetscErrorCode SNESMonitorJacUpdateSpectrum(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
141 PETSC_EXTERN PetscErrorCode SNESMonitorFields(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
142 PETSC_EXTERN PetscErrorCode KSPMonitorSNESResidual(KSP, PetscInt, PetscReal, PetscViewerAndFormat *);
143 PETSC_EXTERN PetscErrorCode KSPMonitorSNESResidualDrawLG(KSP, PetscInt, PetscReal, PetscViewerAndFormat *);
144 PETSC_EXTERN PetscErrorCode KSPMonitorSNESResidualDrawLGCreate(PetscViewer, PetscViewerFormat, void *, PetscViewerAndFormat **);
145 
146 PETSC_EXTERN PetscErrorCode SNESSetTolerances(SNES, PetscReal, PetscReal, PetscReal, PetscInt, PetscInt);
147 PETSC_EXTERN PetscErrorCode SNESSetDivergenceTolerance(SNES, PetscReal);
148 PETSC_EXTERN PetscErrorCode SNESGetTolerances(SNES, PetscReal *, PetscReal *, PetscReal *, PetscInt *, PetscInt *);
149 PETSC_EXTERN PetscErrorCode SNESGetDivergenceTolerance(SNES, PetscReal *);
150 PETSC_EXTERN PetscErrorCode SNESSetTrustRegionTolerance(SNES, PetscReal);
151 PETSC_EXTERN PetscErrorCode SNESGetForceIteration(SNES, PetscBool *);
152 PETSC_EXTERN PetscErrorCode SNESSetForceIteration(SNES, PetscBool);
153 PETSC_EXTERN PetscErrorCode SNESGetIterationNumber(SNES, PetscInt *);
154 PETSC_EXTERN PetscErrorCode SNESSetIterationNumber(SNES, PetscInt);
155 
156 /*E
157     SNESNewtonTRFallbackType - type of fallback in case the solution of the trust-region subproblem is outside of the radius
158 
159    Values:
160 +  `SNES_TR_FALLBACK_NEWTON` - use scaled Newton step
161 .  `SNES_TR_FALLBACK_CAUCHY` - use Cauchy direction
162 -  `SNES_TR_FALLBACK_DOGLEG` - use dogleg method
163 
164    Level: intermediate
165 
166 .seealso: [](ch_snes), `SNES`, `SNESNEWTONTR`, `SNESNEWTONTRDC`
167 E*/
168 typedef enum {
169   SNES_TR_FALLBACK_NEWTON,
170   SNES_TR_FALLBACK_CAUCHY,
171   SNES_TR_FALLBACK_DOGLEG,
172 } SNESNewtonTRFallbackType;
173 
174 PETSC_EXTERN const char *const SNESNewtonTRFallbackTypes[];
175 
176 PETSC_EXTERN PetscErrorCode SNESNewtonTRSetPreCheck(SNES, PetscErrorCode (*)(SNES, Vec, Vec, PetscBool *, void *), void *ctx);
177 PETSC_EXTERN PetscErrorCode SNESNewtonTRGetPreCheck(SNES, PetscErrorCode (**)(SNES, Vec, Vec, PetscBool *, void *), void **ctx);
178 PETSC_EXTERN PetscErrorCode SNESNewtonTRSetPostCheck(SNES, PetscErrorCode (*)(SNES, Vec, Vec, Vec, PetscBool *, PetscBool *, void *), void *ctx);
179 PETSC_EXTERN PetscErrorCode SNESNewtonTRGetPostCheck(SNES, PetscErrorCode (**)(SNES, Vec, Vec, Vec, PetscBool *, PetscBool *, void *), void **ctx);
180 PETSC_EXTERN PetscErrorCode SNESNewtonTRSetFallbackType(SNES, SNESNewtonTRFallbackType);
181 PETSC_EXTERN PetscErrorCode SNESNewtonTRPreCheck(SNES, Vec, Vec, PetscBool *);
182 PETSC_EXTERN PetscErrorCode SNESNewtonTRPostCheck(SNES, Vec, Vec, Vec, PetscBool *, PetscBool *);
183 
184 /* TRDC API, to be removed after 3.19 */
185 PETSC_EXTERN PetscErrorCode SNESNewtonTRDCGetRhoFlag(SNES, PetscBool *);
186 PETSC_EXTERN PetscErrorCode SNESNewtonTRDCSetPreCheck(SNES, PetscErrorCode (*)(SNES, Vec, Vec, PetscBool *, void *), void *ctx);
187 PETSC_EXTERN PetscErrorCode SNESNewtonTRDCGetPreCheck(SNES, PetscErrorCode (**)(SNES, Vec, Vec, PetscBool *, void *), void **ctx);
188 PETSC_EXTERN PetscErrorCode SNESNewtonTRDCSetPostCheck(SNES, PetscErrorCode (*)(SNES, Vec, Vec, Vec, PetscBool *, PetscBool *, void *), void *ctx);
189 PETSC_EXTERN PetscErrorCode SNESNewtonTRDCGetPostCheck(SNES, PetscErrorCode (**)(SNES, Vec, Vec, Vec, PetscBool *, PetscBool *, void *), void **ctx);
190 
191 PETSC_EXTERN PetscErrorCode SNESGetNonlinearStepFailures(SNES, PetscInt *);
192 PETSC_EXTERN PetscErrorCode SNESSetMaxNonlinearStepFailures(SNES, PetscInt);
193 PETSC_EXTERN PetscErrorCode SNESGetMaxNonlinearStepFailures(SNES, PetscInt *);
194 PETSC_EXTERN PetscErrorCode SNESGetNumberFunctionEvals(SNES, PetscInt *);
195 
196 PETSC_EXTERN PetscErrorCode SNESSetLagPreconditioner(SNES, PetscInt);
197 PETSC_EXTERN PetscErrorCode SNESGetLagPreconditioner(SNES, PetscInt *);
198 PETSC_EXTERN PetscErrorCode SNESSetLagJacobian(SNES, PetscInt);
199 PETSC_EXTERN PetscErrorCode SNESGetLagJacobian(SNES, PetscInt *);
200 PETSC_EXTERN PetscErrorCode SNESSetLagPreconditionerPersists(SNES, PetscBool);
201 PETSC_EXTERN PetscErrorCode SNESSetLagJacobianPersists(SNES, PetscBool);
202 PETSC_EXTERN PetscErrorCode SNESSetGridSequence(SNES, PetscInt);
203 PETSC_EXTERN PetscErrorCode SNESGetGridSequence(SNES, PetscInt *);
204 
205 PETSC_EXTERN PetscErrorCode SNESGetLinearSolveIterations(SNES, PetscInt *);
206 PETSC_EXTERN PetscErrorCode SNESGetLinearSolveFailures(SNES, PetscInt *);
207 PETSC_EXTERN PetscErrorCode SNESSetMaxLinearSolveFailures(SNES, PetscInt);
208 PETSC_EXTERN PetscErrorCode SNESGetMaxLinearSolveFailures(SNES, PetscInt *);
209 PETSC_EXTERN PetscErrorCode SNESSetCountersReset(SNES, PetscBool);
210 
211 PETSC_EXTERN PetscErrorCode SNESKSPSetUseEW(SNES, PetscBool);
212 PETSC_EXTERN PetscErrorCode SNESKSPGetUseEW(SNES, PetscBool *);
213 PETSC_EXTERN PetscErrorCode SNESKSPSetParametersEW(SNES, PetscInt, PetscReal, PetscReal, PetscReal, PetscReal, PetscReal, PetscReal);
214 PETSC_EXTERN PetscErrorCode SNESKSPGetParametersEW(SNES, PetscInt *, PetscReal *, PetscReal *, PetscReal *, PetscReal *, PetscReal *, PetscReal *);
215 
216 #include <petscdrawtypes.h>
217 PETSC_EXTERN PetscErrorCode SNESMonitorLGRange(SNES, PetscInt, PetscReal, void *);
218 
219 PETSC_EXTERN PetscErrorCode SNESSetApplicationContext(SNES, void *);
220 PETSC_EXTERN PetscErrorCode SNESGetApplicationContext(SNES, void *);
221 PETSC_EXTERN PetscErrorCode SNESSetComputeApplicationContext(SNES, PetscErrorCode (*)(SNES, void **), PetscErrorCode (*)(void **));
222 
223 PETSC_EXTERN PetscErrorCode SNESPythonSetType(SNES, const char[]);
224 PETSC_EXTERN PetscErrorCode SNESPythonGetType(SNES, const char *[]);
225 
226 PETSC_EXTERN PetscErrorCode SNESSetFunctionDomainError(SNES);
227 PETSC_EXTERN PetscErrorCode SNESGetFunctionDomainError(SNES, PetscBool *);
228 PETSC_EXTERN PetscErrorCode SNESGetJacobianDomainError(SNES, PetscBool *);
229 PETSC_EXTERN PetscErrorCode SNESSetJacobianDomainError(SNES);
230 PETSC_EXTERN PetscErrorCode SNESSetCheckJacobianDomainError(SNES, PetscBool);
231 PETSC_EXTERN PetscErrorCode SNESGetCheckJacobianDomainError(SNES, PetscBool *);
232 
233 #define SNES_CONVERGED_TR_DELTA_DEPRECATED SNES_CONVERGED_TR_DELTA PETSC_DEPRECATED_ENUM(3, 12, 0, "SNES_DIVERGED_TR_DELTA", )
234 /*E
235     SNESConvergedReason - reason a `SNESSolve()` was determined to have converged or diverged
236 
237    Values:
238 +  `SNES_CONVERGED_FNORM_ABS` - 2-norm(F) <= abstol
239 .  `SNES_CONVERGED_FNORM_RELATIVE` - 2-norm(F) <= rtol*2-norm(F(x_0)) where x_0 is the initial guess
240 .  `SNES_CONVERGED_SNORM_RELATIVE` - The 2-norm of the last step <= stol * 2-norm(x) where x is the current
241 .  `SNES_DIVERGED_FUNCTION_COUNT` - The user provided function has been called more times than the maximum set in `SNESSetTolerances()`
242 .  `SNES_DIVERGED_DTOL` - The norm of the function has increased by a factor of divtol set with `SNESSetDivergenceTolerance()`
243 .  `SNES_DIVERGED_FNORM_NAN` - the 2-norm of the current function evaluation is not-a-number (NaN), this
244       is usually caused by a division of 0 by 0.
245 .  `SNES_DIVERGED_MAX_IT` - `SNESSolve()` has reached the maximum number of iterations requested
246 .  `SNES_DIVERGED_LINE_SEARCH` - The line search has failed. This only occurs for `SNES` solvers that use a line search
247 .  `SNES_DIVERGED_LOCAL_MIN` - the algorithm seems to have stagnated at a local minimum that is not zero.
248 -  `SNES_CONERGED_ITERATING` - this only occurs if `SNESGetConvergedReason()` is called during the `SNESSolve()`
249 
250    Level: beginner
251 
252     Notes:
253    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
254    testing with `-pc_type lu` to eliminate the linear solver as the cause of the problem).
255 
256    `SNES_DIVERGED_LOCAL_MIN` can only occur when using the line-search variant of `SNES`.
257        The line search wants to minimize Q(alpha) = 1/2 || F(x + alpha s) ||^2_2  this occurs
258        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
259        you get Q'(alpha) = -F(x)^T F'(x)^(-1)^T F'(x+alpha s)F(x+alpha s); when alpha = 0
260        Q'(0) = - ||F(x)||^2_2 which is always NEGATIVE if F'(x) is invertible. This means the Newton
261        direction is a descent direction and the line search should succeed if alpha is small enough.
262 
263        If F'(x) is NOT invertible AND F'(x)^T F(x) = 0 then Q'(0) = 0 and the Newton direction
264        is NOT a descent direction so the line search will fail. All one can do at this point
265        is change the initial guess and try again.
266 
267        An alternative explanation: Newton's method can be regarded as replacing the function with
268        its linear approximation and minimizing the 2-norm of that. That is F(x+s) approx F(x) + F'(x)s
269        so we minimize || F(x) + F'(x) s ||^2_2; do this using Least Squares. If F'(x) is invertible then
270        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
271        exists a nontrivial (that is F'(x)s != 0) solution to the equation and this direction is
272        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)
273        = - (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
274        and F'(x)^T F'(x) has no negative eigenvalues Q'(0) < 0 so s is a descent direction and the line
275        search should succeed for small enough alpha.
276 
277        Note that this RARELY happens in practice. Far more likely the linear system is not being solved
278        (well enough?) or the Jacobian is wrong.
279 
280    `SNES_DIVERGED_MAX_IT` means that the solver reached the maximum number of iterations without satisfying any
281    convergence criteria. `SNES_CONVERGED_ITS` means that `SNESConvergedSkip()` was chosen as the convergence test;
282    thus the usual convergence criteria have not been checked and may or may not be satisfied.
283 
284 .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `KSPConvergedReason`, `SNESSetConvergenceTest()`, `SNESSetTolerances()`
285 E*/
286 typedef enum {                       /* converged */
287   SNES_CONVERGED_FNORM_ABS      = 2, /* ||F|| < atol */
288   SNES_CONVERGED_FNORM_RELATIVE = 3, /* ||F|| < rtol*||F_initial|| */
289   SNES_CONVERGED_SNORM_RELATIVE = 4, /* Newton computed step size small; || delta x || < stol || x ||*/
290   SNES_CONVERGED_ITS            = 5, /* maximum iterations reached */
291   SNES_BREAKOUT_INNER_ITER      = 6, /* Flag to break out of inner loop after checking custom convergence. */
292                                      /* it is used in multi-phase flow when state changes */
293   /* diverged */
294   SNES_DIVERGED_FUNCTION_DOMAIN      = -1, /* the new x location passed the function is not in the domain of F */
295   SNES_DIVERGED_FUNCTION_COUNT       = -2,
296   SNES_DIVERGED_LINEAR_SOLVE         = -3, /* the linear solve failed */
297   SNES_DIVERGED_FNORM_NAN            = -4,
298   SNES_DIVERGED_MAX_IT               = -5,
299   SNES_DIVERGED_LINE_SEARCH          = -6,  /* the line search failed */
300   SNES_DIVERGED_INNER                = -7,  /* inner solve failed */
301   SNES_DIVERGED_LOCAL_MIN            = -8,  /* || J^T b || is small, implies converged to local minimum of F() */
302   SNES_DIVERGED_DTOL                 = -9,  /* || F || > divtol*||F_initial|| */
303   SNES_DIVERGED_JACOBIAN_DOMAIN      = -10, /* Jacobian calculation does not make sense */
304   SNES_DIVERGED_TR_DELTA             = -11,
305   SNES_CONVERGED_TR_DELTA_DEPRECATED = -11,
306 
307   SNES_CONVERGED_ITERATING = 0
308 } SNESConvergedReason;
309 PETSC_EXTERN const char *const *SNESConvergedReasons;
310 
311 /*MC
312      SNES_CONVERGED_FNORM_ABS - 2-norm(F) <= abstol
313 
314    Level: beginner
315 
316 .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`
317 M*/
318 
319 /*MC
320      SNES_CONVERGED_FNORM_RELATIVE - 2-norm(F) <= rtol*2-norm(F(x_0)) where x_0 is the initial guess
321 
322    Level: beginner
323 
324 .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`
325 M*/
326 
327 /*MC
328      SNES_CONVERGED_SNORM_RELATIVE - The 2-norm of the last step <= stol * 2-norm(x) where x is the current
329           solution and stol is the 4th argument to `SNESSetTolerances()`
330 
331      Options Database Keys:
332       -snes_stol <stol> - the step tolerance
333 
334    Level: beginner
335 
336 .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`
337 M*/
338 
339 /*MC
340      SNES_DIVERGED_FUNCTION_COUNT - The user provided function has been called more times then the final
341          argument to `SNESSetTolerances()`
342 
343    Level: beginner
344 
345 .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`
346 M*/
347 
348 /*MC
349      SNES_DIVERGED_DTOL - The norm of the function has increased by a factor of divtol set with `SNESSetDivergenceTolerance()`
350 
351    Level: beginner
352 
353 .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`, `SNESSetDivergenceTolerance()`
354 M*/
355 
356 /*MC
357      SNES_DIVERGED_FNORM_NAN - the 2-norm of the current function evaluation is not-a-number (NaN), this
358       is usually caused by a division of 0 by 0.
359 
360    Level: beginner
361 
362 .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`
363 M*/
364 
365 /*MC
366      SNES_DIVERGED_MAX_IT - SNESSolve() has reached the maximum number of iterations requested
367 
368    Level: beginner
369 
370 .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`
371 M*/
372 
373 /*MC
374      SNES_DIVERGED_LINE_SEARCH - The line search has failed. This only occurs for a `SNES` solvers that use a line search
375 
376    Level: beginner
377 
378 .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`, `SNESLineSearch`
379 M*/
380 
381 /*MC
382      SNES_DIVERGED_LOCAL_MIN - the algorithm seems to have stagnated at a local minimum that is not zero.
383         See the manual page for `SNESConvergedReason` for more details
384 
385    Level: beginner
386 
387 .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`
388 M*/
389 
390 /*MC
391      SNES_CONERGED_ITERATING - this only occurs if `SNESGetConvergedReason()` is called during the `SNESSolve()`
392 
393    Level: beginner
394 
395 .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`
396 M*/
397 
398 PETSC_EXTERN PetscErrorCode SNESSetConvergenceTest(SNES, PetscErrorCode (*)(SNES, PetscInt, PetscReal, PetscReal, PetscReal, SNESConvergedReason *, void *), void *, PetscErrorCode (*)(void *));
399 PETSC_EXTERN PetscErrorCode SNESConvergedDefault(SNES, PetscInt, PetscReal, PetscReal, PetscReal, SNESConvergedReason *, void *);
400 PETSC_EXTERN PetscErrorCode SNESConvergedSkip(SNES, PetscInt, PetscReal, PetscReal, PetscReal, SNESConvergedReason *, void *);
401 PETSC_EXTERN PetscErrorCode SNESConvergedCorrectPressure(SNES, PetscInt, PetscReal, PetscReal, PetscReal, SNESConvergedReason *, void *);
402 PETSC_EXTERN PetscErrorCode SNESGetConvergedReason(SNES, SNESConvergedReason *);
403 PETSC_EXTERN PetscErrorCode SNESGetConvergedReasonString(SNES, const char **);
404 PETSC_EXTERN PetscErrorCode SNESSetConvergedReason(SNES, SNESConvergedReason);
405 
406 PETSC_DEPRECATED_FUNCTION(3, 5, 0, "SNESConvergedSkip()", ) static inline void SNESSkipConverged(void)
407 { /* never called */
408 }
409 #define SNESSkipConverged (SNESSkipConverged, SNESConvergedSkip)
410 
411 /* --------- Solving systems of nonlinear equations --------------- */
412 PETSC_EXTERN PetscErrorCode SNESSetFunction(SNES, Vec, PetscErrorCode (*)(SNES, Vec, Vec, void *), void *);
413 PETSC_EXTERN PetscErrorCode SNESGetFunction(SNES, Vec *, PetscErrorCode (**)(SNES, Vec, Vec, void *), void **);
414 PETSC_EXTERN PetscErrorCode SNESComputeFunction(SNES, Vec, Vec);
415 PETSC_EXTERN PetscErrorCode SNESComputeMFFunction(SNES, Vec, Vec);
416 PETSC_EXTERN PetscErrorCode SNESSetInitialFunction(SNES, Vec);
417 
418 PETSC_EXTERN PetscErrorCode SNESSetJacobian(SNES, Mat, Mat, PetscErrorCode (*)(SNES, Vec, Mat, Mat, void *), void *);
419 PETSC_EXTERN PetscErrorCode SNESGetJacobian(SNES, Mat *, Mat *, PetscErrorCode (**)(SNES, Vec, Mat, Mat, void *), void **);
420 PETSC_EXTERN PetscErrorCode SNESObjectiveComputeFunctionDefaultFD(SNES, Vec, Vec, void *);
421 PETSC_EXTERN PetscErrorCode SNESComputeJacobianDefault(SNES, Vec, Mat, Mat, void *);
422 PETSC_EXTERN PetscErrorCode SNESComputeJacobianDefaultColor(SNES, Vec, Mat, Mat, void *);
423 PETSC_EXTERN PetscErrorCode SNESPruneJacobianColor(SNES, Mat, Mat);
424 PETSC_EXTERN PetscErrorCode SNESSetComputeInitialGuess(SNES, PetscErrorCode (*)(SNES, Vec, void *), void *);
425 PETSC_EXTERN PetscErrorCode SNESSetPicard(SNES, Vec, PetscErrorCode (*)(SNES, Vec, Vec, void *), Mat, Mat, PetscErrorCode (*)(SNES, Vec, Mat, Mat, void *), void *);
426 PETSC_EXTERN PetscErrorCode SNESGetPicard(SNES, Vec *, PetscErrorCode (**)(SNES, Vec, Vec, void *), Mat *, Mat *, PetscErrorCode (**)(SNES, Vec, Mat, Mat, void *), void **);
427 PETSC_EXTERN PetscErrorCode SNESPicardComputeFunction(SNES, Vec, Vec, void *);
428 PETSC_EXTERN PetscErrorCode SNESPicardComputeMFFunction(SNES, Vec, Vec, void *);
429 PETSC_EXTERN PetscErrorCode SNESPicardComputeJacobian(SNES, Vec, Mat, Mat, void *);
430 
431 PETSC_EXTERN PetscErrorCode SNESSetObjective(SNES, PetscErrorCode (*)(SNES, Vec, PetscReal *, void *), void *);
432 PETSC_EXTERN PetscErrorCode SNESGetObjective(SNES, PetscErrorCode (**)(SNES, Vec, PetscReal *, void *), void **);
433 PETSC_EXTERN PetscErrorCode SNESComputeObjective(SNES, Vec, PetscReal *);
434 
435 /*E
436     SNESNormSchedule - Frequency with which the norm is computed during a nonliner solve
437 
438    Values:
439 +   `SNES_NORM_DEFAULT` - use the default behavior for the current `SNESType`
440 .   `SNES_NORM_NONE` - avoid all norm computations
441 .   `SNES_NORM_ALWAYS` - compute the norms whenever possible
442 .   `SNES_NORM_INITIAL_ONLY` - compute the norm only when the algorithm starts
443 .   `SNES_NORM_FINAL_ONLY` - compute the norm only when the algorithm finishes
444 -   `SNES_NORM_INITIAL_FINAL_ONLY` - compute the norm at the start and end of the algorithm
445 
446    Level: advanced
447 
448    Notes:
449    Support for these is highly dependent on the solver.
450 
451    Some options limit the convergence tests that can be used.
452 
453    The `SNES_NORM_NONE` option is most commonly used when the nonlinear solver is being used as a smoother, for example for `SNESFAS`
454 
455    This is primarily used to turn off extra norm and function computation
456    when the solvers are composed.
457 
458 .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `KSPSetNormType()`,
459           `KSPSetConvergenceTest()`, `KSPSetPCSide()`
460 E*/
461 typedef enum {
462   SNES_NORM_DEFAULT            = -1,
463   SNES_NORM_NONE               = 0,
464   SNES_NORM_ALWAYS             = 1,
465   SNES_NORM_INITIAL_ONLY       = 2,
466   SNES_NORM_FINAL_ONLY         = 3,
467   SNES_NORM_INITIAL_FINAL_ONLY = 4
468 } SNESNormSchedule;
469 PETSC_EXTERN const char *const *const SNESNormSchedules;
470 
471 /*MC
472     SNES_NORM_NONE - Don't compute function and its L2 norm when possible
473 
474    Level: advanced
475 
476     Note:
477     This is most useful for stationary solvers with a fixed number of iterations used as smoothers.
478 
479 .seealso: [](ch_snes), `SNESNormSchedule`, `SNES`, `SNESSetNormSchedule()`, `SNES_NORM_DEFAULT`
480 M*/
481 
482 /*MC
483     SNES_NORM_ALWAYS - Compute the function and its L2 norm at each iteration.
484 
485    Level: advanced
486 
487     Note:
488     Most solvers will use this no matter what norm type is passed to them.
489 
490 .seealso: [](ch_snes), `SNESNormSchedule`, `SNES`, `SNESSetNormSchedule()`, `SNES_NORM_NONE`
491 M*/
492 
493 /*MC
494     SNES_NORM_INITIAL_ONLY - Compute the function and its L2 at iteration 0, but do not update it.
495 
496    Level: advanced
497 
498    Notes:
499    This method is useful in composed methods, when a true solution might actually be found before `SNESSolve()` is called.
500    This option enables the solve to abort on the zeroth iteration if this is the case.
501 
502    For solvers that require the computation of the L2 norm of the function as part of the method, this merely cancels
503    the norm computation at the last iteration (if possible).
504 
505 .seealso: [](ch_snes), `SNESNormSchedule`, `SNES`, `SNESSetNormSchedule()`, `SNES_NORM_FINAL_ONLY`, `SNES_NORM_INITIAL_FINAL_ONLY`
506 M*/
507 
508 /*MC
509     SNES_NORM_FINAL_ONLY - Compute the function and its L2 norm on only the final iteration.
510 
511    Level: advanced
512 
513    Note:
514    For solvers that require the computation of the L2 norm of the function as part of the method, behaves
515    exactly as `SNES_NORM_DEFAULT`.  This method is useful when the function is gotten after `SNESSolve()` and
516    used in subsequent computation for methods that do not need the norm computed during the rest of the
517    solution procedure.
518 
519 .seealso: [](ch_snes), `SNESNormSchedule`, `SNES`, `SNESSetNormSchedule()`, `SNES_NORM_INITIAL_ONLY`, `SNES_NORM_INITIAL_FINAL_ONLY`
520 M*/
521 
522 /*MC
523     SNES_NORM_INITIAL_FINAL_ONLY - Compute the function and its L2 norm on only the initial and final iterations.
524 
525    Level: advanced
526 
527    Note:
528    This method combines the benefits of `SNES_NORM_INITIAL_ONLY` and `SNES_NORM_FINAL_ONLY`.
529 
530 .seealso: [](ch_snes), `SNESNormSchedule`, `SNES`, `SNESSetNormSchedule()`, `SNES_NORM_SNES_NORM_INITIAL_ONLY`, `SNES_NORM_FINAL_ONLY`
531 M*/
532 
533 PETSC_EXTERN PetscErrorCode SNESSetNormSchedule(SNES, SNESNormSchedule);
534 PETSC_EXTERN PetscErrorCode SNESGetNormSchedule(SNES, SNESNormSchedule *);
535 PETSC_EXTERN PetscErrorCode SNESSetFunctionNorm(SNES, PetscReal);
536 PETSC_EXTERN PetscErrorCode SNESGetFunctionNorm(SNES, PetscReal *);
537 PETSC_EXTERN PetscErrorCode SNESGetUpdateNorm(SNES, PetscReal *);
538 PETSC_EXTERN PetscErrorCode SNESGetSolutionNorm(SNES, PetscReal *);
539 
540 /*E
541     SNESFunctionType - Type of function computed
542 
543    Values:
544 +  `SNES_FUNCTION_DEFAULT` - the default behavior for the current `SNESType`
545 .  `SNES_FUNCTION_UNPRECONDITIONED` - the original function provided
546 -  `SNES_FUNCTION_PRECONDITIONED` - the modification of the function by the preconditioner
547 
548    Level: advanced
549 
550    Note:
551    Support for these is dependent on the solver.
552 
553 .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `KSPSetNormType()`,
554           `KSPSetConvergenceTest()`, `KSPSetPCSide()`
555 E*/
556 typedef enum {
557   SNES_FUNCTION_DEFAULT          = -1,
558   SNES_FUNCTION_UNPRECONDITIONED = 0,
559   SNES_FUNCTION_PRECONDITIONED   = 1
560 } SNESFunctionType;
561 PETSC_EXTERN const char *const *const SNESFunctionTypes;
562 
563 PETSC_EXTERN PetscErrorCode SNESSetFunctionType(SNES, SNESFunctionType);
564 PETSC_EXTERN PetscErrorCode SNESGetFunctionType(SNES, SNESFunctionType *);
565 
566 PETSC_EXTERN PetscErrorCode SNESSetNGS(SNES, PetscErrorCode (*)(SNES, Vec, Vec, void *), void *);
567 PETSC_EXTERN PetscErrorCode SNESGetNGS(SNES, PetscErrorCode (**)(SNES, Vec, Vec, void *), void **);
568 PETSC_EXTERN PetscErrorCode SNESComputeNGS(SNES, Vec, Vec);
569 
570 PETSC_EXTERN PetscErrorCode SNESNGSSetSweeps(SNES, PetscInt);
571 PETSC_EXTERN PetscErrorCode SNESNGSGetSweeps(SNES, PetscInt *);
572 PETSC_EXTERN PetscErrorCode SNESNGSSetTolerances(SNES, PetscReal, PetscReal, PetscReal, PetscInt);
573 PETSC_EXTERN PetscErrorCode SNESNGSGetTolerances(SNES, PetscReal *, PetscReal *, PetscReal *, PetscInt *);
574 
575 PETSC_EXTERN PetscErrorCode SNESSetAlwaysComputesFinalResidual(SNES, PetscBool);
576 PETSC_EXTERN PetscErrorCode SNESGetAlwaysComputesFinalResidual(SNES, PetscBool *);
577 
578 PETSC_EXTERN PetscErrorCode SNESShellGetContext(SNES, void *);
579 PETSC_EXTERN PetscErrorCode SNESShellSetContext(SNES, void *);
580 PETSC_EXTERN PetscErrorCode SNESShellSetSolve(SNES, PetscErrorCode (*)(SNES, Vec));
581 
582 /* --------- Routines specifically for line search methods --------------- */
583 
584 /*S
585      SNESLineSearch - Abstract PETSc object that manages line-search operations for nonlinear solvers
586 
587    Level: beginner
588 
589 .seealso: [](ch_snes), `SNESLineSearchType`, `SNESLineSearchCreate()`, `SNESLineSearchSetType()`, `SNES`
590 S*/
591 typedef struct _p_LineSearch *SNESLineSearch;
592 
593 /*J
594     SNESLineSearchType - String with the name of a PETSc line search method `SNESLineSearch`
595 
596    Level: beginner
597 
598    Values:
599 +  `SNESLINESEARCHBASIC` - (or equivalently `SNESLINESEARCHNONE`) Simple damping line search, defaults to using the full Newton step
600 .  `SNESLINESEARCHBT` - Backtracking line search over the L2 norm of the function
601 .  `SNESLINESEARCHL2` - Secant line search over the L2 norm of the function
602 .  `SNESLINESEARCHCP` - Critical point secant line search assuming F(x) = grad G(x) for some unknown G(x)
603 .  `SNESLINESEARCHNLEQERR` - Affine-covariant error-oriented linesearch
604 -  `SNESLINESEARCHSHELL` - User provided `SNESLineSearch` implementation
605 
606 .seealso: [](ch_snes), `SNESLineSearch`, `SNESLineSearchSetType()`, `SNES`
607 J*/
608 typedef const char *SNESLineSearchType;
609 #define SNESLINESEARCHBT        "bt"
610 #define SNESLINESEARCHNLEQERR   "nleqerr"
611 #define SNESLINESEARCHBASIC     "basic"
612 #define SNESLINESEARCHNONE      "none"
613 #define SNESLINESEARCHL2        "l2"
614 #define SNESLINESEARCHCP        "cp"
615 #define SNESLINESEARCHSHELL     "shell"
616 #define SNESLINESEARCHNCGLINEAR "ncglinear"
617 
618 PETSC_EXTERN PetscFunctionList SNESList;
619 PETSC_EXTERN PetscClassId      SNESLINESEARCH_CLASSID;
620 PETSC_EXTERN PetscFunctionList SNESLineSearchList;
621 
622 #define SNES_LINESEARCH_ORDER_LINEAR    1
623 #define SNES_LINESEARCH_ORDER_QUADRATIC 2
624 #define SNES_LINESEARCH_ORDER_CUBIC     3
625 
626 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode (*SNESLineSearchVIProjectFunc)(SNES, Vec);
627 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode (*SNESLineSearchVINormFunc)(SNES, Vec, Vec, PetscReal *);
628 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode (*SNESLineSearchApplyFunc)(SNESLineSearch);
629 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode (*SNESLineSearchUserFunc)(SNESLineSearch, void *);
630 
631 PETSC_EXTERN PetscErrorCode SNESLineSearchCreate(MPI_Comm, SNESLineSearch *);
632 PETSC_EXTERN PetscErrorCode SNESLineSearchReset(SNESLineSearch);
633 PETSC_EXTERN PetscErrorCode SNESLineSearchView(SNESLineSearch, PetscViewer);
634 PETSC_EXTERN PetscErrorCode SNESLineSearchDestroy(SNESLineSearch *);
635 PETSC_EXTERN PetscErrorCode SNESLineSearchGetType(SNESLineSearch, SNESLineSearchType *);
636 PETSC_EXTERN PetscErrorCode SNESLineSearchSetType(SNESLineSearch, SNESLineSearchType);
637 PETSC_EXTERN PetscErrorCode SNESLineSearchSetFromOptions(SNESLineSearch);
638 PETSC_EXTERN PetscErrorCode SNESLineSearchSetFunction(SNESLineSearch, PetscErrorCode (*)(SNES, Vec, Vec));
639 PETSC_EXTERN PetscErrorCode SNESLineSearchSetUp(SNESLineSearch);
640 PETSC_EXTERN PetscErrorCode SNESLineSearchApply(SNESLineSearch, Vec, Vec, PetscReal *, Vec);
641 PETSC_EXTERN PetscErrorCode SNESLineSearchPreCheck(SNESLineSearch, Vec, Vec, PetscBool *);
642 PETSC_EXTERN PetscErrorCode SNESLineSearchPostCheck(SNESLineSearch, Vec, Vec, Vec, PetscBool *, PetscBool *);
643 PETSC_EXTERN PetscErrorCode SNESLineSearchSetWorkVecs(SNESLineSearch, PetscInt);
644 
645 /* set the functions for precheck and postcheck */
646 
647 PETSC_EXTERN PetscErrorCode SNESLineSearchSetPreCheck(SNESLineSearch, PetscErrorCode (*)(SNESLineSearch, Vec, Vec, PetscBool *, void *), void *ctx);
648 PETSC_EXTERN PetscErrorCode SNESLineSearchSetPostCheck(SNESLineSearch, PetscErrorCode (*)(SNESLineSearch, Vec, Vec, Vec, PetscBool *, PetscBool *, void *), void *ctx);
649 
650 PETSC_EXTERN PetscErrorCode SNESLineSearchGetPreCheck(SNESLineSearch, PetscErrorCode (**)(SNESLineSearch, Vec, Vec, PetscBool *, void *), void **ctx);
651 PETSC_EXTERN PetscErrorCode SNESLineSearchGetPostCheck(SNESLineSearch, PetscErrorCode (**)(SNESLineSearch, Vec, Vec, Vec, PetscBool *, PetscBool *, void *), void **ctx);
652 
653 /* set the functions for VI-specific line search operations */
654 
655 PETSC_EXTERN PetscErrorCode SNESLineSearchSetVIFunctions(SNESLineSearch, SNESLineSearchVIProjectFunc, SNESLineSearchVINormFunc);
656 PETSC_EXTERN PetscErrorCode SNESLineSearchGetVIFunctions(SNESLineSearch, SNESLineSearchVIProjectFunc *, SNESLineSearchVINormFunc *);
657 
658 /* pointers to the associated SNES in order to be able to get the function evaluation out */
659 PETSC_EXTERN PetscErrorCode SNESLineSearchSetSNES(SNESLineSearch, SNES);
660 PETSC_EXTERN PetscErrorCode SNESLineSearchGetSNES(SNESLineSearch, SNES *);
661 
662 /* set and get the parameters and vectors */
663 PETSC_EXTERN PetscErrorCode SNESLineSearchGetTolerances(SNESLineSearch, PetscReal *, PetscReal *, PetscReal *, PetscReal *, PetscReal *, PetscInt *);
664 PETSC_EXTERN PetscErrorCode SNESLineSearchSetTolerances(SNESLineSearch, PetscReal, PetscReal, PetscReal, PetscReal, PetscReal, PetscInt);
665 
666 PETSC_EXTERN PetscErrorCode SNESLineSearchPreCheckPicard(SNESLineSearch, Vec, Vec, PetscBool *, void *);
667 
668 PETSC_EXTERN PetscErrorCode SNESLineSearchGetLambda(SNESLineSearch, PetscReal *);
669 PETSC_EXTERN PetscErrorCode SNESLineSearchSetLambda(SNESLineSearch, PetscReal);
670 
671 PETSC_EXTERN PetscErrorCode SNESLineSearchGetDamping(SNESLineSearch, PetscReal *);
672 PETSC_EXTERN PetscErrorCode SNESLineSearchSetDamping(SNESLineSearch, PetscReal);
673 
674 PETSC_EXTERN PetscErrorCode SNESLineSearchGetOrder(SNESLineSearch, PetscInt *order);
675 PETSC_EXTERN PetscErrorCode SNESLineSearchSetOrder(SNESLineSearch, PetscInt order);
676 
677 /*E
678     SNESLineSearchReason - indication if the line search has succeeded or failed and why
679 
680   Values:
681 +  `SNES_LINESEARCH_SUCCEEDED` - the line search succeeded
682 .  `SNES_LINESEARCH_FAILED_NANORINF` - a not a number of infinity appeared in the computions
683 .  `SNES_LINESEARCH_FAILED_DOMAIN` - the function was evaluated outside of its domain, see `SNESSetFunctionDomainError()` and `SNESSetJacobianDomainError()`
684 .  `SNES_LINESEARCH_FAILED_REDUCT` - the linear search failed to get the requested decrease in its norm or objective
685 .  `SNES_LINESEARCH_FAILED_USER` - used by `SNESLINESEARCHNLEQERR` to indicate the user changed the search direction inappropriately
686 -  `SNES_LINESEARCH_FAILED_FUNCTION` - indicates the maximum number of function evaluations allowed has been surpassed, `SNESConvergedReason` is also
687                                      set to `SNES_DIVERGED_FUNCTION_COUNT`
688 
689    Level: intermediate
690 
691    Developer Note:
692    Some of these reasons overlap with values of `SNESConvergedReason`
693 
694 .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `KSPConvergedReason`, `SNESSetConvergenceTest()`,
695           `SNESSetFunctionDomainError()` and `SNESSetJacobianDomainError()`
696 E*/
697 typedef enum {
698   SNES_LINESEARCH_SUCCEEDED,
699   SNES_LINESEARCH_FAILED_NANORINF,
700   SNES_LINESEARCH_FAILED_DOMAIN,
701   SNES_LINESEARCH_FAILED_REDUCT, /* INSUFFICIENT REDUCTION */
702   SNES_LINESEARCH_FAILED_USER,
703   SNES_LINESEARCH_FAILED_FUNCTION
704 } SNESLineSearchReason;
705 
706 PETSC_EXTERN PetscErrorCode SNESLineSearchGetReason(SNESLineSearch, SNESLineSearchReason *);
707 PETSC_EXTERN PetscErrorCode SNESLineSearchSetReason(SNESLineSearch, SNESLineSearchReason);
708 
709 PETSC_EXTERN PetscErrorCode SNESLineSearchGetVecs(SNESLineSearch, Vec *, Vec *, Vec *, Vec *, Vec *);
710 PETSC_EXTERN PetscErrorCode SNESLineSearchSetVecs(SNESLineSearch, Vec, Vec, Vec, Vec, Vec);
711 
712 PETSC_EXTERN PetscErrorCode SNESLineSearchGetNorms(SNESLineSearch, PetscReal *, PetscReal *, PetscReal *);
713 PETSC_EXTERN PetscErrorCode SNESLineSearchSetNorms(SNESLineSearch, PetscReal, PetscReal, PetscReal);
714 PETSC_EXTERN PetscErrorCode SNESLineSearchComputeNorms(SNESLineSearch);
715 PETSC_EXTERN PetscErrorCode SNESLineSearchSetComputeNorms(SNESLineSearch, PetscBool);
716 
717 PETSC_EXTERN PetscErrorCode SNESLineSearchMonitor(SNESLineSearch);
718 PETSC_EXTERN PetscErrorCode SNESLineSearchMonitorSet(SNESLineSearch, PetscErrorCode (*)(SNESLineSearch, void *), void *, PetscErrorCode (*)(void **));
719 PETSC_EXTERN PetscErrorCode SNESLineSearchMonitorSetFromOptions(SNESLineSearch, const char[], const char[], const char[], PetscErrorCode (*)(SNESLineSearch, PetscViewerAndFormat *), PetscErrorCode (*)(SNESLineSearch, PetscViewerAndFormat *));
720 PETSC_EXTERN PetscErrorCode SNESLineSearchMonitorCancel(SNESLineSearch);
721 PETSC_EXTERN PetscErrorCode SNESLineSearchSetDefaultMonitor(SNESLineSearch, PetscViewer);
722 PETSC_EXTERN PetscErrorCode SNESLineSearchGetDefaultMonitor(SNESLineSearch, PetscViewer *);
723 PETSC_EXTERN PetscErrorCode SNESLineSearchMonitorSolutionUpdate(SNESLineSearch, PetscViewerAndFormat *);
724 
725 PETSC_EXTERN PetscErrorCode SNESLineSearchAppendOptionsPrefix(SNESLineSearch, const char prefix[]);
726 PETSC_EXTERN PetscErrorCode SNESLineSearchGetOptionsPrefix(SNESLineSearch, const char *prefix[]);
727 
728 /* Shell interface functions */
729 PETSC_EXTERN PetscErrorCode SNESLineSearchShellSetUserFunc(SNESLineSearch, SNESLineSearchUserFunc, void *);
730 PETSC_EXTERN PetscErrorCode SNESLineSearchShellGetUserFunc(SNESLineSearch, SNESLineSearchUserFunc *, void **);
731 
732 /* BT interface functions */
733 PETSC_EXTERN PetscErrorCode SNESLineSearchBTSetAlpha(SNESLineSearch, PetscReal);
734 PETSC_EXTERN PetscErrorCode SNESLineSearchBTGetAlpha(SNESLineSearch, PetscReal *);
735 
736 /*register line search types */
737 PETSC_EXTERN PetscErrorCode SNESLineSearchRegister(const char[], PetscErrorCode (*)(SNESLineSearch));
738 
739 /* Routines for VI solver */
740 PETSC_EXTERN PetscErrorCode SNESVISetVariableBounds(SNES, Vec, Vec);
741 PETSC_EXTERN PetscErrorCode SNESVIGetVariableBounds(SNES, Vec *, Vec *);
742 PETSC_EXTERN PetscErrorCode SNESVISetComputeVariableBounds(SNES, PetscErrorCode (*)(SNES, Vec, Vec));
743 PETSC_EXTERN PetscErrorCode SNESVIGetInactiveSet(SNES, IS *);
744 PETSC_EXTERN PetscErrorCode SNESVIGetActiveSetIS(SNES, Vec, Vec, IS *);
745 PETSC_EXTERN PetscErrorCode SNESVIComputeInactiveSetFnorm(SNES, Vec, Vec, PetscReal *);
746 PETSC_EXTERN PetscErrorCode SNESVISetRedundancyCheck(SNES, PetscErrorCode (*)(SNES, IS, IS *, void *), void *);
747 PETSC_EXTERN PetscErrorCode SNESVIComputeMeritFunction(Vec, PetscReal *, PetscReal *);
748 PETSC_EXTERN PetscErrorCode SNESVIComputeFunction(SNES, Vec, Vec, void *);
749 PETSC_EXTERN PetscErrorCode DMSetVI(DM, IS);
750 PETSC_EXTERN PetscErrorCode DMDestroyVI(DM);
751 
752 PETSC_EXTERN PetscErrorCode SNESTestLocalMin(SNES);
753 
754 /* Should this routine be private? */
755 PETSC_EXTERN PetscErrorCode SNESComputeJacobian(SNES, Vec, Mat, Mat);
756 PETSC_EXTERN PetscErrorCode SNESTestJacobian(SNES);
757 
758 PETSC_EXTERN PetscErrorCode SNESSetDM(SNES, DM);
759 PETSC_EXTERN PetscErrorCode SNESGetDM(SNES, DM *);
760 PETSC_EXTERN PetscErrorCode SNESSetNPC(SNES, SNES);
761 PETSC_EXTERN PetscErrorCode SNESGetNPC(SNES, SNES *);
762 PETSC_EXTERN PetscErrorCode SNESHasNPC(SNES, PetscBool *);
763 PETSC_EXTERN PetscErrorCode SNESApplyNPC(SNES, Vec, Vec, Vec);
764 PETSC_EXTERN PetscErrorCode SNESGetNPCFunction(SNES, Vec, PetscReal *);
765 PETSC_EXTERN PetscErrorCode SNESComputeFunctionDefaultNPC(SNES, Vec, Vec);
766 PETSC_EXTERN PetscErrorCode SNESSetNPCSide(SNES, PCSide);
767 PETSC_EXTERN PetscErrorCode SNESGetNPCSide(SNES, PCSide *);
768 PETSC_EXTERN PetscErrorCode SNESSetLineSearch(SNES, SNESLineSearch);
769 PETSC_EXTERN PetscErrorCode SNESGetLineSearch(SNES, SNESLineSearch *);
770 
771 PETSC_DEPRECATED_FUNCTION(3, 4, 0, "SNESGetLineSearch()", ) static inline PetscErrorCode SNESGetSNESLineSearch(SNES snes, SNESLineSearch *ls)
772 {
773   return SNESGetLineSearch(snes, ls);
774 }
775 PETSC_DEPRECATED_FUNCTION(3, 4, 0, "SNESSetLineSearch()", ) static inline PetscErrorCode SNESSetSNESLineSearch(SNES snes, SNESLineSearch ls)
776 {
777   return SNESSetLineSearch(snes, ls);
778 }
779 
780 PETSC_EXTERN PetscErrorCode SNESSetUpMatrices(SNES);
781 PETSC_EXTERN PetscErrorCode DMSNESSetFunction(DM, PetscErrorCode (*)(SNES, Vec, Vec, void *), void *);
782 PETSC_EXTERN PetscErrorCode DMSNESGetFunction(DM, PetscErrorCode (**)(SNES, Vec, Vec, void *), void **);
783 PETSC_EXTERN PetscErrorCode DMSNESSetFunctionContextDestroy(DM, PetscErrorCode (*)(void *));
784 PETSC_EXTERN PetscErrorCode DMSNESSetMFFunction(DM, PetscErrorCode (*)(SNES, Vec, Vec, void *), void *);
785 PETSC_EXTERN PetscErrorCode DMSNESSetNGS(DM, PetscErrorCode (*)(SNES, Vec, Vec, void *), void *);
786 PETSC_EXTERN PetscErrorCode DMSNESGetNGS(DM, PetscErrorCode (**)(SNES, Vec, Vec, void *), void **);
787 PETSC_EXTERN PetscErrorCode DMSNESSetJacobian(DM, PetscErrorCode (*)(SNES, Vec, Mat, Mat, void *), void *);
788 PETSC_EXTERN PetscErrorCode DMSNESGetJacobian(DM, PetscErrorCode (**)(SNES, Vec, Mat, Mat, void *), void **);
789 PETSC_EXTERN PetscErrorCode DMSNESSetJacobianContextDestroy(DM, PetscErrorCode (*)(void *));
790 PETSC_EXTERN PetscErrorCode DMSNESSetPicard(DM, PetscErrorCode (*)(SNES, Vec, Vec, void *), PetscErrorCode (*)(SNES, Vec, Mat, Mat, void *), void *);
791 PETSC_EXTERN PetscErrorCode DMSNESGetPicard(DM, PetscErrorCode (**)(SNES, Vec, Vec, void *), PetscErrorCode (**)(SNES, Vec, Mat, Mat, void *), void **);
792 PETSC_EXTERN PetscErrorCode DMSNESSetObjective(DM, PetscErrorCode (*)(SNES, Vec, PetscReal *, void *), void *);
793 PETSC_EXTERN PetscErrorCode DMSNESGetObjective(DM, PetscErrorCode (**)(SNES, Vec, PetscReal *, void *), void **);
794 PETSC_EXTERN PetscErrorCode DMCopyDMSNES(DM, DM);
795 
796 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode (*DMDASNESFunction)(DMDALocalInfo *, void *, void *, void *);
797 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode (*DMDASNESJacobian)(DMDALocalInfo *, void *, Mat, Mat, void *);
798 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode (*DMDASNESObjective)(DMDALocalInfo *, void *, PetscReal *, void *);
799 
800 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode (*DMDASNESFunctionVec)(DMDALocalInfo *, Vec, Vec, void *);
801 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode (*DMDASNESJacobianVec)(DMDALocalInfo *, Vec, Mat, Mat, void *);
802 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode (*DMDASNESObjectiveVec)(DMDALocalInfo *, Vec, PetscReal *, void *);
803 
804 PETSC_EXTERN PetscErrorCode DMDASNESSetFunctionLocal(DM, InsertMode, DMDASNESFunction, void *);
805 PETSC_EXTERN PetscErrorCode DMDASNESSetJacobianLocal(DM, DMDASNESJacobian, void *);
806 PETSC_EXTERN PetscErrorCode DMDASNESSetObjectiveLocal(DM, DMDASNESObjective, void *);
807 PETSC_EXTERN PetscErrorCode DMDASNESSetPicardLocal(DM, InsertMode, PetscErrorCode (*)(DMDALocalInfo *, void *, void *, void *), PetscErrorCode (*)(DMDALocalInfo *, void *, Mat, Mat, void *), void *);
808 
809 PETSC_EXTERN PetscErrorCode DMDASNESSetFunctionLocalVec(DM, InsertMode, DMDASNESFunctionVec, void *);
810 PETSC_EXTERN PetscErrorCode DMDASNESSetJacobianLocalVec(DM, DMDASNESJacobianVec, void *);
811 PETSC_EXTERN PetscErrorCode DMDASNESSetObjectiveLocalVec(DM, DMDASNESObjectiveVec, void *);
812 
813 PETSC_EXTERN PetscErrorCode DMSNESSetBoundaryLocal(DM, PetscErrorCode (*)(DM, Vec, void *), void *);
814 PETSC_EXTERN PetscErrorCode DMSNESSetFunctionLocal(DM, PetscErrorCode (*)(DM, Vec, Vec, void *), void *);
815 PETSC_EXTERN PetscErrorCode DMSNESSetJacobianLocal(DM, PetscErrorCode (*)(DM, Vec, Mat, Mat, void *), void *);
816 PETSC_EXTERN PetscErrorCode DMSNESGetBoundaryLocal(DM, PetscErrorCode (**)(DM, Vec, void *), void **);
817 PETSC_EXTERN PetscErrorCode DMSNESGetFunctionLocal(DM, PetscErrorCode (**)(DM, Vec, Vec, void *), void **);
818 PETSC_EXTERN PetscErrorCode DMSNESGetJacobianLocal(DM, PetscErrorCode (**)(DM, Vec, Mat, Mat, void *), void **);
819 
820 /* Routines for Multiblock solver */
821 PETSC_EXTERN PetscErrorCode SNESMultiblockSetFields(SNES, const char[], PetscInt, const PetscInt *);
822 PETSC_EXTERN PetscErrorCode SNESMultiblockSetIS(SNES, const char[], IS);
823 PETSC_EXTERN PetscErrorCode SNESMultiblockSetBlockSize(SNES, PetscInt);
824 PETSC_EXTERN PetscErrorCode SNESMultiblockSetType(SNES, PCCompositeType);
825 PETSC_EXTERN PetscErrorCode SNESMultiblockGetSubSNES(SNES, PetscInt *, SNES *[]);
826 
827 /*J
828     SNESMSType - String with the name of a PETSc `SNESMS` method.
829 
830    Level: intermediate
831 
832 .seealso: [](ch_snes), `SNESMS`, `SNESMSGetType()`, `SNESMSSetType()`, `SNES`
833 J*/
834 typedef const char *SNESMSType;
835 #define SNESMSM62       "m62"
836 #define SNESMSEULER     "euler"
837 #define SNESMSJAMESON83 "jameson83"
838 #define SNESMSVLTP11    "vltp11"
839 #define SNESMSVLTP21    "vltp21"
840 #define SNESMSVLTP31    "vltp31"
841 #define SNESMSVLTP41    "vltp41"
842 #define SNESMSVLTP51    "vltp51"
843 #define SNESMSVLTP61    "vltp61"
844 
845 PETSC_EXTERN PetscErrorCode SNESMSRegister(SNESMSType, PetscInt, PetscInt, PetscReal, const PetscReal[], const PetscReal[], const PetscReal[]);
846 PETSC_EXTERN PetscErrorCode SNESMSRegisterAll(void);
847 PETSC_EXTERN PetscErrorCode SNESMSGetType(SNES, SNESMSType *);
848 PETSC_EXTERN PetscErrorCode SNESMSSetType(SNES, SNESMSType);
849 PETSC_EXTERN PetscErrorCode SNESMSGetDamping(SNES, PetscReal *);
850 PETSC_EXTERN PetscErrorCode SNESMSSetDamping(SNES, PetscReal);
851 PETSC_EXTERN PetscErrorCode SNESMSFinalizePackage(void);
852 PETSC_EXTERN PetscErrorCode SNESMSInitializePackage(void);
853 PETSC_EXTERN PetscErrorCode SNESMSRegisterDestroy(void);
854 
855 /*MC
856    SNESNGMRESRestartType - the restart approach used by `SNESNGMRES`
857 
858    Level: intermediate
859 
860   Values:
861 +   `SNES_NGMRES_RESTART_NONE` - never restart
862 .   `SNES_NGMRES_RESTART_DIFFERENCE` - restart based upon difference criteria
863 -   `SNES_NGMRES_RESTART_PERIODIC` - restart after a fixed number of iterations
864 
865   Options Database Keys:
866 + -snes_ngmres_restart_type<difference,periodic,none> - set the restart type
867 - -snes_ngmres_restart[30]                            - sets the number of iterations before restart for periodic
868 
869 .seealso: `SNES, `SNESNGMRES`, `SNESNGMRESSetSelectType()`, `SNESNGMRESGetSelectType()`, `SNESNGMRESSetRestartType()`,
870           `SNESNGMRESGetRestartType()`, `SNESNGMRESSelectType`
871 M*/
872 typedef enum {
873   SNES_NGMRES_RESTART_NONE       = 0,
874   SNES_NGMRES_RESTART_PERIODIC   = 1,
875   SNES_NGMRES_RESTART_DIFFERENCE = 2
876 } SNESNGMRESRestartType;
877 PETSC_EXTERN const char *const SNESNGMRESRestartTypes[];
878 
879 /*MC
880    SNESNGMRESSelectType - the approach used by `SNESNGMRES` to determine how the candidate solution and
881   combined solution are used to create the next iterate.
882 
883    Level: intermediate
884 
885    Values:
886 +   `SNES_NGMRES_SELECT_NONE` - choose the combined solution all the time
887 .   `SNES_NGMRES_SELECT_DIFFERENCE` - choose based upon the selection criteria
888 -   `SNES_NGMRES_SELECT_LINESEARCH` - choose based upon line search combination
889 
890   Options Database Key:
891 . -snes_ngmres_select_type<difference,none,linesearch> - select type
892 
893 .seealso: `SNES, `SNESNGMRES`, `SNESNGMRESSetSelectType()`, `SNESNGMRESGetSelectType()`, `SNESNGMRESSetRestartType()`,
894           `SNESNGMRESGetRestartType()`, `SNESNGMRESRestartType`
895 M*/
896 typedef enum {
897   SNES_NGMRES_SELECT_NONE       = 0,
898   SNES_NGMRES_SELECT_DIFFERENCE = 1,
899   SNES_NGMRES_SELECT_LINESEARCH = 2
900 } SNESNGMRESSelectType;
901 PETSC_EXTERN const char *const SNESNGMRESSelectTypes[];
902 
903 PETSC_EXTERN PetscErrorCode SNESNGMRESSetRestartType(SNES, SNESNGMRESRestartType);
904 PETSC_EXTERN PetscErrorCode SNESNGMRESSetSelectType(SNES, SNESNGMRESSelectType);
905 PETSC_EXTERN PetscErrorCode SNESNGMRESSetRestartFmRise(SNES, PetscBool);
906 PETSC_EXTERN PetscErrorCode SNESNGMRESGetRestartFmRise(SNES, PetscBool *);
907 
908 /*MC
909    SNESNCGType - the conjugate update approach for `SNESNCG`
910 
911    Level: intermediate
912 
913    Values:
914 +   `SNES_NCG_FR` - Fletcher-Reeves update
915 .   `SNES_NCG_PRP` - Polak-Ribiere-Polyak update, the default and the only one that tolerates generalized search directions
916 .   `SNES_NCG_HS` - Hestenes-Steifel update
917 .   `SNES_NCG_DY` - Dai-Yuan update
918 -   `SNES_NCG_CD` - Conjugate Descent update
919 
920   Options Database Key:
921 . -snes_ncg_type<fr,prp,hs,dy,cd> - select type
922 
923 .seealso: `SNES, `SNESNCG`, `SNESNCGSetType()`
924 M*/
925 typedef enum {
926   SNES_NCG_FR  = 0,
927   SNES_NCG_PRP = 1,
928   SNES_NCG_HS  = 2,
929   SNES_NCG_DY  = 3,
930   SNES_NCG_CD  = 4
931 } SNESNCGType;
932 PETSC_EXTERN const char *const SNESNCGTypes[];
933 
934 PETSC_EXTERN PetscErrorCode SNESNCGSetType(SNES, SNESNCGType);
935 
936 /*MC
937    SNESQNScaleType - the scaling type used by `SNESQN`
938 
939    Level: intermediate
940 
941    Values:
942 +   `SNES_QN_SCALE_NONE` - don't scale the problem
943 .   `SNES_QN_SCALE_SCALAR` - use Shanno scaling
944 .   `SNES_QN_SCALE_DIAGONAL` - scale with a diagonalized BFGS formula (see Gilbert and Lemarechal 1989), available
945 -   `SNES_QN_SCALE_JACOBIAN` - scale by solving a linear system coming from the Jacobian you provided with `SNESSetJacobian()`
946                                computed at the first iteration of `SNESQN` and at ever restart.
947 
948     Options Database Key:
949 . -snes_qn_scale_type <diagonal,none,scalar,jacobian> - Scaling type
950 
951 .seealso: `SNES, `SNESQN`, `SNESQNSetScaleType()`, `SNESQNType`, `SNESQNSetType()`, `SNESQNSetRestartType()`, `SNESQNRestartType`
952 M*/
953 typedef enum {
954   SNES_QN_SCALE_DEFAULT  = 0,
955   SNES_QN_SCALE_NONE     = 1,
956   SNES_QN_SCALE_SCALAR   = 2,
957   SNES_QN_SCALE_DIAGONAL = 3,
958   SNES_QN_SCALE_JACOBIAN = 4
959 } SNESQNScaleType;
960 PETSC_EXTERN const char *const SNESQNScaleTypes[];
961 
962 /*MC
963    SNESQNRestartType - the restart approached used by `SNESQN`
964 
965    Level: intermediate
966 
967    Values:
968 +   `SNES_QN_RESTART_NONE` - never restart
969 .   `SNES_QN_RESTART_POWELL` - restart based upon descent criteria
970 -   `SNES_QN_RESTART_PERIODIC` - restart after a fixed number of iterations
971 
972   Options Database Keys:
973 + -snes_qn_restart_type <powell,periodic,none> - set the restart type
974 - -snes_qn_m <m>                               - sets the number of stored updates and the restart period for periodic
975 
976 .seealso: `SNES, `SNESQN`, `SNESQNSetScaleType()`, `SNESQNType`, `SNESQNSetType()`, `SNESQNSetRestartType()`, `SNESQNScaleType`
977 M*/
978 typedef enum {
979   SNES_QN_RESTART_DEFAULT  = 0,
980   SNES_QN_RESTART_NONE     = 1,
981   SNES_QN_RESTART_POWELL   = 2,
982   SNES_QN_RESTART_PERIODIC = 3
983 } SNESQNRestartType;
984 PETSC_EXTERN const char *const SNESQNRestartTypes[];
985 
986 /*MC
987    SNESQNType - the type used by `SNESQN`
988 
989    Level: intermediate
990 
991   Values:
992 +   `SNES_QN_LBFGS` - LBFGS variant
993 .   `SNES_QN_BROYDEN` - Broyden variant
994 -   `SNES_QN_BADBROYDEN` - Bad Broyden variant
995 
996   Options Database Key:
997 . -snes_qn_type <lbfgs,broyden,badbroyden> - quasi-Newton type
998 
999 .seealso: `SNES, `SNESQN`, `SNESQNSetScaleType()`, `SNESQNSetType()`, `SNESQNScaleType`, `SNESQNRestartType`, `SNESQNSetRestartType()`
1000 M*/
1001 typedef enum {
1002   SNES_QN_LBFGS      = 0,
1003   SNES_QN_BROYDEN    = 1,
1004   SNES_QN_BADBROYDEN = 2
1005 } SNESQNType;
1006 PETSC_EXTERN const char *const SNESQNTypes[];
1007 
1008 PETSC_EXTERN PetscErrorCode SNESQNSetType(SNES, SNESQNType);
1009 PETSC_EXTERN PetscErrorCode SNESQNSetScaleType(SNES, SNESQNScaleType);
1010 PETSC_EXTERN PetscErrorCode SNESQNSetRestartType(SNES, SNESQNRestartType);
1011 
1012 PETSC_EXTERN PetscErrorCode SNESNASMGetType(SNES, PCASMType *);
1013 PETSC_EXTERN PetscErrorCode SNESNASMSetType(SNES, PCASMType);
1014 PETSC_EXTERN PetscErrorCode SNESNASMGetSubdomains(SNES, PetscInt *, SNES **, VecScatter **, VecScatter **, VecScatter **);
1015 PETSC_EXTERN PetscErrorCode SNESNASMSetSubdomains(SNES, PetscInt, SNES *, VecScatter *, VecScatter *, VecScatter *);
1016 PETSC_EXTERN PetscErrorCode SNESNASMSetDamping(SNES, PetscReal);
1017 PETSC_EXTERN PetscErrorCode SNESNASMGetDamping(SNES, PetscReal *);
1018 PETSC_EXTERN PetscErrorCode SNESNASMGetSubdomainVecs(SNES, PetscInt *, Vec **, Vec **, Vec **, Vec **);
1019 PETSC_EXTERN PetscErrorCode SNESNASMSetComputeFinalJacobian(SNES, PetscBool);
1020 PETSC_EXTERN PetscErrorCode SNESNASMGetSNES(SNES, PetscInt, SNES *);
1021 PETSC_EXTERN PetscErrorCode SNESNASMGetNumber(SNES, PetscInt *);
1022 PETSC_EXTERN PetscErrorCode SNESNASMSetWeight(SNES, Vec);
1023 
1024 typedef enum {
1025   SNES_COMPOSITE_ADDITIVE,
1026   SNES_COMPOSITE_MULTIPLICATIVE,
1027   SNES_COMPOSITE_ADDITIVEOPTIMAL
1028 } SNESCompositeType;
1029 PETSC_EXTERN const char *const SNESCompositeTypes[];
1030 
1031 PETSC_EXTERN PetscErrorCode SNESCompositeSetType(SNES, SNESCompositeType);
1032 PETSC_EXTERN PetscErrorCode SNESCompositeAddSNES(SNES, SNESType);
1033 PETSC_EXTERN PetscErrorCode SNESCompositeGetSNES(SNES, PetscInt, SNES *);
1034 PETSC_EXTERN PetscErrorCode SNESCompositeGetNumber(SNES, PetscInt *);
1035 PETSC_EXTERN PetscErrorCode SNESCompositeSetDamping(SNES, PetscInt, PetscReal);
1036 
1037 PETSC_EXTERN PetscErrorCode SNESPatchSetDiscretisationInfo(SNES, PetscInt, DM *, PetscInt *, PetscInt *, const PetscInt **, const PetscInt *, PetscInt, const PetscInt *, PetscInt, const PetscInt *);
1038 PETSC_EXTERN PetscErrorCode SNESPatchSetComputeOperator(SNES, PetscErrorCode (*func)(PC, PetscInt, Vec, Mat, IS, PetscInt, const PetscInt *, const PetscInt *, void *), void *);
1039 PETSC_EXTERN PetscErrorCode SNESPatchSetComputeFunction(SNES, PetscErrorCode (*func)(PC, PetscInt, Vec, Vec, IS, PetscInt, const PetscInt *, const PetscInt *, void *), void *);
1040 PETSC_EXTERN PetscErrorCode SNESPatchSetConstructType(SNES, PCPatchConstructType, PetscErrorCode (*func)(PC, PetscInt *, IS **, IS *, void *), void *);
1041 PETSC_EXTERN PetscErrorCode SNESPatchSetCellNumbering(SNES, PetscSection);
1042 
1043 /*E
1044     SNESFASType - Determines the type of nonlinear multigrid method that is run.
1045 
1046    Values:
1047 +  `SNES_FAS_MULTIPLICATIVE` (default) - traditional V or W cycle as determined by `SNESFASSetCycles()`
1048 .  `SNES_FAS_ADDITIVE`                 - additive FAS cycle
1049 .  `SNES_FAS_FULL`                     - full FAS cycle
1050 -  `SNES_FAS_KASKADE`                  - Kaskade FAS cycle
1051 
1052    Level: beginner
1053 
1054 .seealso: [](ch_snes), `SNESFAS`, `PCMGSetType()`, `PCMGType`
1055 E*/
1056 typedef enum {
1057   SNES_FAS_MULTIPLICATIVE,
1058   SNES_FAS_ADDITIVE,
1059   SNES_FAS_FULL,
1060   SNES_FAS_KASKADE
1061 } SNESFASType;
1062 PETSC_EXTERN const char *const SNESFASTypes[];
1063 
1064 /* called on the finest level FAS instance*/
1065 PETSC_EXTERN PetscErrorCode SNESFASSetType(SNES, SNESFASType);
1066 PETSC_EXTERN PetscErrorCode SNESFASGetType(SNES, SNESFASType *);
1067 PETSC_EXTERN PetscErrorCode SNESFASSetLevels(SNES, PetscInt, MPI_Comm *);
1068 PETSC_EXTERN PetscErrorCode SNESFASGetLevels(SNES, PetscInt *);
1069 PETSC_EXTERN PetscErrorCode SNESFASGetCycleSNES(SNES, PetscInt, SNES *);
1070 PETSC_EXTERN PetscErrorCode SNESFASSetNumberSmoothUp(SNES, PetscInt);
1071 PETSC_EXTERN PetscErrorCode SNESFASSetNumberSmoothDown(SNES, PetscInt);
1072 PETSC_EXTERN PetscErrorCode SNESFASSetCycles(SNES, PetscInt);
1073 PETSC_EXTERN PetscErrorCode SNESFASSetMonitor(SNES, PetscViewerAndFormat *, PetscBool);
1074 PETSC_EXTERN PetscErrorCode SNESFASSetLog(SNES, PetscBool);
1075 
1076 PETSC_EXTERN PetscErrorCode SNESFASSetGalerkin(SNES, PetscBool);
1077 PETSC_EXTERN PetscErrorCode SNESFASGetGalerkin(SNES, PetscBool *);
1078 PETSC_EXTERN PetscErrorCode SNESFASGalerkinFunctionDefault(SNES, Vec, Vec, void *);
1079 
1080 /* called on any level -- "Cycle" FAS instance */
1081 PETSC_EXTERN PetscErrorCode SNESFASCycleGetSmoother(SNES, SNES *);
1082 PETSC_EXTERN PetscErrorCode SNESFASCycleGetSmootherUp(SNES, SNES *);
1083 PETSC_EXTERN PetscErrorCode SNESFASCycleGetSmootherDown(SNES, SNES *);
1084 PETSC_EXTERN PetscErrorCode SNESFASCycleGetCorrection(SNES, SNES *);
1085 PETSC_EXTERN PetscErrorCode SNESFASCycleGetInterpolation(SNES, Mat *);
1086 PETSC_EXTERN PetscErrorCode SNESFASCycleGetRestriction(SNES, Mat *);
1087 PETSC_EXTERN PetscErrorCode SNESFASCycleGetInjection(SNES, Mat *);
1088 PETSC_EXTERN PetscErrorCode SNESFASCycleGetRScale(SNES, Vec *);
1089 PETSC_EXTERN PetscErrorCode SNESFASCycleSetCycles(SNES, PetscInt);
1090 PETSC_EXTERN PetscErrorCode SNESFASCycleIsFine(SNES, PetscBool *);
1091 
1092 /* called on the (outer) finest level FAS to set/get parameters on any level instance */
1093 PETSC_EXTERN PetscErrorCode SNESFASSetInterpolation(SNES, PetscInt, Mat);
1094 PETSC_EXTERN PetscErrorCode SNESFASGetInterpolation(SNES, PetscInt, Mat *);
1095 PETSC_EXTERN PetscErrorCode SNESFASSetRestriction(SNES, PetscInt, Mat);
1096 PETSC_EXTERN PetscErrorCode SNESFASGetRestriction(SNES, PetscInt, Mat *);
1097 PETSC_EXTERN PetscErrorCode SNESFASSetInjection(SNES, PetscInt, Mat);
1098 PETSC_EXTERN PetscErrorCode SNESFASGetInjection(SNES, PetscInt, Mat *);
1099 PETSC_EXTERN PetscErrorCode SNESFASSetRScale(SNES, PetscInt, Vec);
1100 PETSC_EXTERN PetscErrorCode SNESFASGetRScale(SNES, PetscInt, Vec *);
1101 PETSC_EXTERN PetscErrorCode SNESFASSetContinuation(SNES, PetscBool);
1102 
1103 PETSC_EXTERN PetscErrorCode SNESFASGetSmoother(SNES, PetscInt, SNES *);
1104 PETSC_EXTERN PetscErrorCode SNESFASGetSmootherUp(SNES, PetscInt, SNES *);
1105 PETSC_EXTERN PetscErrorCode SNESFASGetSmootherDown(SNES, PetscInt, SNES *);
1106 PETSC_EXTERN PetscErrorCode SNESFASGetCoarseSolve(SNES, SNES *);
1107 
1108 /* parameters for full FAS */
1109 PETSC_EXTERN PetscErrorCode SNESFASFullSetDownSweep(SNES, PetscBool);
1110 PETSC_EXTERN PetscErrorCode SNESFASCreateCoarseVec(SNES, Vec *);
1111 PETSC_EXTERN PetscErrorCode SNESFASRestrict(SNES, Vec, Vec);
1112 PETSC_EXTERN PetscErrorCode SNESFASFullSetTotal(SNES, PetscBool);
1113 PETSC_EXTERN PetscErrorCode SNESFASFullGetTotal(SNES, PetscBool *);
1114 
1115 PETSC_EXTERN PetscErrorCode DMSNESCheckDiscretization(SNES, DM, PetscReal, Vec, PetscReal, PetscReal[]);
1116 PETSC_EXTERN PetscErrorCode DMSNESCheckResidual(SNES, DM, Vec, PetscReal, PetscReal *);
1117 PETSC_EXTERN PetscErrorCode DMSNESCheckJacobian(SNES, DM, Vec, PetscReal, PetscBool *, PetscReal *);
1118 PETSC_EXTERN PetscErrorCode DMSNESCheckFromOptions(SNES, Vec);
1119 PETSC_EXTERN PetscErrorCode DMSNESComputeJacobianAction(DM, Vec, Vec, Vec, void *);
1120 PETSC_EXTERN PetscErrorCode DMSNESCreateJacobianMF(DM, Vec, void *, Mat *);
1121 
1122 #endif
1123