xref: /petsc/include/petscsnes.h (revision 47bfdf3fa30783d319821566bb96996bc8fc6067)
1 /*
2     User interface for the nonlinear solvers package.
3 */
4 #pragma once
5 
6 #include <petscksp.h>
7 #include <petscdmtypes.h>
8 #include <petscfvtypes.h>
9 #include <petscdmdatypes.h>
10 #include <petscsnestypes.h>
11 
12 /* SUBMANSEC = SNES */
13 
14 /*J
15    SNESType - String with the name of a PETSc `SNES` method.
16 
17    Level: beginner
18 
19 .seealso: [](doc_nonlinsolve), [](ch_snes), `SNESSetType()`, `SNES`, `SNESCreate()`, `SNESDestroy()`, `SNESSetFromOptions()`
20 J*/
21 typedef const char *SNESType;
22 #define SNESNEWTONLS         "newtonls"
23 #define SNESNEWTONTR         "newtontr"
24 #define SNESNEWTONTRDC       "newtontrdc"
25 #define SNESPYTHON           "python"
26 #define SNESNRICHARDSON      "nrichardson"
27 #define SNESKSPONLY          "ksponly"
28 #define SNESKSPTRANSPOSEONLY "ksptransposeonly"
29 #define SNESVINEWTONRSLS     "vinewtonrsls"
30 #define SNESVINEWTONSSLS     "vinewtonssls"
31 #define SNESNGMRES           "ngmres"
32 #define SNESQN               "qn"
33 #define SNESSHELL            "shell"
34 #define SNESNGS              "ngs"
35 #define SNESNCG              "ncg"
36 #define SNESFAS              "fas"
37 #define SNESMS               "ms"
38 #define SNESNASM             "nasm"
39 #define SNESANDERSON         "anderson"
40 #define SNESASPIN            "aspin"
41 #define SNESCOMPOSITE        "composite"
42 #define SNESPATCH            "patch"
43 
44 /* Logging support */
45 PETSC_EXTERN PetscClassId SNES_CLASSID;
46 PETSC_EXTERN PetscClassId DMSNES_CLASSID;
47 
48 PETSC_EXTERN PetscErrorCode SNESInitializePackage(void);
49 PETSC_EXTERN PetscErrorCode SNESFinalizePackage(void);
50 
51 PETSC_EXTERN PetscErrorCode SNESCreate(MPI_Comm, SNES *);
52 PETSC_EXTERN PetscErrorCode SNESReset(SNES);
53 PETSC_EXTERN PetscErrorCode SNESDestroy(SNES *);
54 PETSC_EXTERN PetscErrorCode SNESSetType(SNES, SNESType);
55 PETSC_EXTERN PetscErrorCode SNESMonitor(SNES, PetscInt, PetscReal);
56 PETSC_EXTERN PetscErrorCode SNESMonitorSet(SNES, PetscErrorCode (*)(SNES, PetscInt, PetscReal, void *), void *, PetscErrorCode (*)(void **));
57 PETSC_EXTERN PetscErrorCode SNESMonitorSetFromOptions(SNES, const char[], const char[], const char[], PetscErrorCode (*)(SNES, PetscInt, PetscReal, PetscViewerAndFormat *), PetscErrorCode (*)(SNES, PetscViewerAndFormat *));
58 PETSC_EXTERN PetscErrorCode SNESMonitorCancel(SNES);
59 PETSC_EXTERN PetscErrorCode SNESMonitorSAWs(SNES, PetscInt, PetscReal, void *);
60 PETSC_EXTERN PetscErrorCode SNESMonitorSAWsCreate(SNES, void **);
61 PETSC_EXTERN PetscErrorCode SNESMonitorSAWsDestroy(void **);
62 PETSC_EXTERN PetscErrorCode SNESSetConvergenceHistory(SNES, PetscReal[], PetscInt[], PetscInt, PetscBool);
63 PETSC_EXTERN PetscErrorCode SNESGetConvergenceHistory(SNES, PetscReal *[], PetscInt *[], PetscInt *);
64 PETSC_EXTERN PetscErrorCode SNESSetUp(SNES);
65 PETSC_EXTERN PetscErrorCode SNESSolve(SNES, Vec, Vec);
66 PETSC_EXTERN PetscErrorCode SNESSetErrorIfNotConverged(SNES, PetscBool);
67 PETSC_EXTERN PetscErrorCode SNESGetErrorIfNotConverged(SNES, PetscBool *);
68 PETSC_EXTERN PetscErrorCode SNESConverged(SNES, PetscInt, PetscReal, PetscReal, PetscReal);
69 
70 PETSC_EXTERN PetscErrorCode SNESSetWorkVecs(SNES, PetscInt);
71 
72 PETSC_EXTERN PetscErrorCode SNESAddOptionsChecker(PetscErrorCode (*)(SNES));
73 
74 PETSC_EXTERN PetscErrorCode SNESRegister(const char[], PetscErrorCode (*)(SNES));
75 
76 PETSC_EXTERN PetscErrorCode SNESGetKSP(SNES, KSP *);
77 PETSC_EXTERN PetscErrorCode SNESSetKSP(SNES, KSP);
78 PETSC_EXTERN PetscErrorCode SNESSetSolution(SNES, Vec);
79 PETSC_EXTERN PetscErrorCode SNESGetSolution(SNES, Vec *);
80 PETSC_EXTERN PetscErrorCode SNESGetSolutionUpdate(SNES, Vec *);
81 PETSC_EXTERN PetscErrorCode SNESGetRhs(SNES, Vec *);
82 PETSC_EXTERN PetscErrorCode SNESView(SNES, PetscViewer);
83 PETSC_EXTERN PetscErrorCode SNESLoad(SNES, PetscViewer);
84 PETSC_EXTERN PetscErrorCode SNESConvergedReasonViewSet(SNES, PetscErrorCode (*)(SNES, void *), void *, PetscErrorCode (*)(void **));
85 PETSC_EXTERN PetscErrorCode SNESViewFromOptions(SNES, PetscObject, const char[]);
86 PETSC_EXTERN PetscErrorCode SNESConvergedReasonView(SNES, PetscViewer);
87 PETSC_EXTERN PetscErrorCode SNESConvergedReasonViewFromOptions(SNES);
88 PETSC_EXTERN PetscErrorCode SNESConvergedReasonViewCancel(SNES);
89 
90 PETSC_DEPRECATED_FUNCTION(3, 14, 0, "SNESConvergedReasonView()", ) static inline PetscErrorCode SNESReasonView(SNES snes, PetscViewer v)
91 {
92   return SNESConvergedReasonView(snes, v);
93 }
94 PETSC_DEPRECATED_FUNCTION(3, 14, 0, "SNESConvergedReasonViewFromOptions()", ) static inline PetscErrorCode SNESReasonViewFromOptions(SNES snes)
95 {
96   return SNESConvergedReasonViewFromOptions(snes);
97 }
98 
99 #define SNES_FILE_CLASSID 1211224
100 
101 PETSC_EXTERN PetscErrorCode SNESSetOptionsPrefix(SNES, const char[]);
102 PETSC_EXTERN PetscErrorCode SNESAppendOptionsPrefix(SNES, const char[]);
103 PETSC_EXTERN PetscErrorCode SNESGetOptionsPrefix(SNES, const char *[]);
104 PETSC_EXTERN PetscErrorCode SNESSetFromOptions(SNES);
105 PETSC_EXTERN PetscErrorCode SNESResetFromOptions(SNES);
106 
107 PETSC_EXTERN PetscErrorCode SNESSetUseMatrixFree(SNES, PetscBool, PetscBool);
108 PETSC_EXTERN PetscErrorCode SNESGetUseMatrixFree(SNES, PetscBool *, PetscBool *);
109 PETSC_EXTERN PetscErrorCode MatCreateSNESMF(SNES, Mat *);
110 PETSC_EXTERN PetscErrorCode MatSNESMFGetSNES(Mat, SNES *);
111 PETSC_EXTERN PetscErrorCode MatSNESMFSetReuseBase(Mat, PetscBool);
112 PETSC_EXTERN PetscErrorCode MatSNESMFGetReuseBase(Mat, PetscBool *);
113 PETSC_EXTERN PetscErrorCode MatMFFDComputeJacobian(SNES, Vec, Mat, Mat, void *);
114 PETSC_EXTERN PetscErrorCode MatCreateSNESMFMore(SNES, Vec, Mat *);
115 PETSC_EXTERN PetscErrorCode MatSNESMFMoreSetParameters(Mat, PetscReal, PetscReal, PetscReal);
116 
117 PETSC_EXTERN PetscErrorCode SNESGetType(SNES, SNESType *);
118 PETSC_EXTERN PetscErrorCode SNESMonitorDefaultSetUp(SNES, PetscViewerAndFormat *);
119 PETSC_EXTERN PetscErrorCode SNESMonitorDefault(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
120 PETSC_EXTERN PetscErrorCode SNESMonitorScaling(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
121 PETSC_EXTERN PetscErrorCode SNESMonitorRange(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
122 PETSC_EXTERN PetscErrorCode SNESMonitorRatio(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
123 PETSC_EXTERN PetscErrorCode SNESMonitorRatioSetUp(SNES, PetscViewerAndFormat *);
124 PETSC_EXTERN PetscErrorCode SNESMonitorSolution(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
125 PETSC_EXTERN PetscErrorCode SNESMonitorResidual(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
126 PETSC_EXTERN PetscErrorCode SNESMonitorSolutionUpdate(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
127 PETSC_EXTERN PetscErrorCode SNESMonitorDefaultShort(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
128 PETSC_EXTERN PetscErrorCode SNESMonitorDefaultField(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
129 PETSC_EXTERN PetscErrorCode SNESMonitorJacUpdateSpectrum(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
130 PETSC_EXTERN PetscErrorCode SNESMonitorFields(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
131 PETSC_EXTERN PetscErrorCode KSPMonitorSNESResidual(KSP, PetscInt, PetscReal, PetscViewerAndFormat *);
132 PETSC_EXTERN PetscErrorCode KSPMonitorSNESResidualDrawLG(KSP, PetscInt, PetscReal, PetscViewerAndFormat *);
133 PETSC_EXTERN PetscErrorCode KSPMonitorSNESResidualDrawLGCreate(PetscViewer, PetscViewerFormat, void *, PetscViewerAndFormat **);
134 
135 PETSC_EXTERN PetscErrorCode SNESSetTolerances(SNES, PetscReal, PetscReal, PetscReal, PetscInt, PetscInt);
136 PETSC_EXTERN PetscErrorCode SNESSetDivergenceTolerance(SNES, PetscReal);
137 PETSC_EXTERN PetscErrorCode SNESGetTolerances(SNES, PetscReal *, PetscReal *, PetscReal *, PetscInt *, PetscInt *);
138 PETSC_EXTERN PetscErrorCode SNESGetDivergenceTolerance(SNES, PetscReal *);
139 PETSC_EXTERN PetscErrorCode SNESSetTrustRegionTolerance(SNES, PetscReal);
140 PETSC_EXTERN PetscErrorCode SNESGetForceIteration(SNES, PetscBool *);
141 PETSC_EXTERN PetscErrorCode SNESSetForceIteration(SNES, PetscBool);
142 PETSC_EXTERN PetscErrorCode SNESGetIterationNumber(SNES, PetscInt *);
143 PETSC_EXTERN PetscErrorCode SNESSetIterationNumber(SNES, PetscInt);
144 
145 /*E
146    SNESNewtonTRFallbackType - type of fallback in case the solution of the trust-region subproblem is outside of the radius
147 
148    Values:
149 +  `SNES_TR_FALLBACK_NEWTON` - use scaled Newton step
150 .  `SNES_TR_FALLBACK_CAUCHY` - use Cauchy direction
151 -  `SNES_TR_FALLBACK_DOGLEG` - use dogleg method
152 
153    Level: intermediate
154 
155 .seealso: [](ch_snes), `SNES`, `SNESNEWTONTR`, `SNESNEWTONTRDC`
156 E*/
157 typedef enum {
158   SNES_TR_FALLBACK_NEWTON,
159   SNES_TR_FALLBACK_CAUCHY,
160   SNES_TR_FALLBACK_DOGLEG,
161 } SNESNewtonTRFallbackType;
162 
163 PETSC_EXTERN const char *const SNESNewtonTRFallbackTypes[];
164 
165 PETSC_EXTERN PetscErrorCode SNESNewtonTRSetPreCheck(SNES, PetscErrorCode (*)(SNES, Vec, Vec, PetscBool *, void *), void *ctx);
166 PETSC_EXTERN PetscErrorCode SNESNewtonTRGetPreCheck(SNES, PetscErrorCode (**)(SNES, Vec, Vec, PetscBool *, void *), void **ctx);
167 PETSC_EXTERN PetscErrorCode SNESNewtonTRSetPostCheck(SNES, PetscErrorCode (*)(SNES, Vec, Vec, Vec, PetscBool *, PetscBool *, void *), void *ctx);
168 PETSC_EXTERN PetscErrorCode SNESNewtonTRGetPostCheck(SNES, PetscErrorCode (**)(SNES, Vec, Vec, Vec, PetscBool *, PetscBool *, void *), void **ctx);
169 PETSC_EXTERN PetscErrorCode SNESNewtonTRSetFallbackType(SNES, SNESNewtonTRFallbackType);
170 PETSC_EXTERN PetscErrorCode SNESNewtonTRPreCheck(SNES, Vec, Vec, PetscBool *);
171 PETSC_EXTERN PetscErrorCode SNESNewtonTRPostCheck(SNES, Vec, Vec, Vec, PetscBool *, PetscBool *);
172 PETSC_EXTERN PetscErrorCode SNESNewtonTRSetNormType(SNES, NormType);
173 
174 /*E
175     SNESNewtonTRQNType - type of quasi-Newton model to use
176 
177    Values:
178 +  `SNES_TR_QN_NONE` - do not use a quasi-Newton model
179 .  `SNES_TR_QN_SAME` - use the same quasi-Newton model for matrix and preconditioner
180 -  `SNES_TR_QN_DIFFERENT` - use different quasi-Newton models for matrix and preconditioner
181 
182    Level: intermediate
183 
184 .seealso: [](ch_snes), `SNES`, `SNESNEWTONTR`
185 E*/
186 typedef enum {
187   SNES_TR_QN_NONE,
188   SNES_TR_QN_SAME,
189   SNES_TR_QN_DIFFERENT,
190 } SNESNewtonTRQNType;
191 
192 PETSC_EXTERN const char *const SNESNewtonTRQNTypes[];
193 
194 PETSC_EXTERN PetscErrorCode SNESNewtonTRSetQNType(SNES, SNESNewtonTRQNType);
195 
196 PETSC_EXTERN PetscErrorCode SNESNewtonTRDCGetRhoFlag(SNES, PetscBool *);
197 PETSC_EXTERN PetscErrorCode SNESNewtonTRDCSetPreCheck(SNES, PetscErrorCode (*)(SNES, Vec, Vec, PetscBool *, void *), void *ctx);
198 PETSC_EXTERN PetscErrorCode SNESNewtonTRDCGetPreCheck(SNES, PetscErrorCode (**)(SNES, Vec, Vec, PetscBool *, void *), void **ctx);
199 PETSC_EXTERN PetscErrorCode SNESNewtonTRDCSetPostCheck(SNES, PetscErrorCode (*)(SNES, Vec, Vec, Vec, PetscBool *, PetscBool *, void *), void *ctx);
200 PETSC_EXTERN PetscErrorCode SNESNewtonTRDCGetPostCheck(SNES, PetscErrorCode (**)(SNES, Vec, Vec, Vec, PetscBool *, PetscBool *, void *), void **ctx);
201 
202 PETSC_EXTERN PetscErrorCode SNESGetNonlinearStepFailures(SNES, PetscInt *);
203 PETSC_EXTERN PetscErrorCode SNESSetMaxNonlinearStepFailures(SNES, PetscInt);
204 PETSC_EXTERN PetscErrorCode SNESGetMaxNonlinearStepFailures(SNES, PetscInt *);
205 PETSC_EXTERN PetscErrorCode SNESGetNumberFunctionEvals(SNES, PetscInt *);
206 
207 PETSC_EXTERN PetscErrorCode SNESSetLagPreconditioner(SNES, PetscInt);
208 PETSC_EXTERN PetscErrorCode SNESGetLagPreconditioner(SNES, PetscInt *);
209 PETSC_EXTERN PetscErrorCode SNESSetLagJacobian(SNES, PetscInt);
210 PETSC_EXTERN PetscErrorCode SNESGetLagJacobian(SNES, PetscInt *);
211 PETSC_EXTERN PetscErrorCode SNESSetLagPreconditionerPersists(SNES, PetscBool);
212 PETSC_EXTERN PetscErrorCode SNESSetLagJacobianPersists(SNES, PetscBool);
213 PETSC_EXTERN PetscErrorCode SNESSetGridSequence(SNES, PetscInt);
214 PETSC_EXTERN PetscErrorCode SNESGetGridSequence(SNES, PetscInt *);
215 
216 PETSC_EXTERN PetscErrorCode SNESGetLinearSolveIterations(SNES, PetscInt *);
217 PETSC_EXTERN PetscErrorCode SNESGetLinearSolveFailures(SNES, PetscInt *);
218 PETSC_EXTERN PetscErrorCode SNESSetMaxLinearSolveFailures(SNES, PetscInt);
219 PETSC_EXTERN PetscErrorCode SNESGetMaxLinearSolveFailures(SNES, PetscInt *);
220 PETSC_EXTERN PetscErrorCode SNESSetCountersReset(SNES, PetscBool);
221 
222 PETSC_EXTERN PetscErrorCode SNESKSPSetUseEW(SNES, PetscBool);
223 PETSC_EXTERN PetscErrorCode SNESKSPGetUseEW(SNES, PetscBool *);
224 PETSC_EXTERN PetscErrorCode SNESKSPSetParametersEW(SNES, PetscInt, PetscReal, PetscReal, PetscReal, PetscReal, PetscReal, PetscReal);
225 PETSC_EXTERN PetscErrorCode SNESKSPGetParametersEW(SNES, PetscInt *, PetscReal *, PetscReal *, PetscReal *, PetscReal *, PetscReal *, PetscReal *);
226 
227 #include <petscdrawtypes.h>
228 PETSC_EXTERN PetscErrorCode SNESMonitorLGRange(SNES, PetscInt, PetscReal, void *);
229 
230 PETSC_EXTERN PetscErrorCode SNESSetApplicationContext(SNES, void *);
231 PETSC_EXTERN PetscErrorCode SNESGetApplicationContext(SNES, void *);
232 PETSC_EXTERN PetscErrorCode SNESSetComputeApplicationContext(SNES, PetscErrorCode (*)(SNES, void **), PetscErrorCode (*)(void **));
233 
234 PETSC_EXTERN PetscErrorCode SNESPythonSetType(SNES, const char[]);
235 PETSC_EXTERN PetscErrorCode SNESPythonGetType(SNES, const char *[]);
236 
237 PETSC_EXTERN PetscErrorCode SNESSetFunctionDomainError(SNES);
238 PETSC_EXTERN PetscErrorCode SNESGetFunctionDomainError(SNES, PetscBool *);
239 PETSC_EXTERN PetscErrorCode SNESGetJacobianDomainError(SNES, PetscBool *);
240 PETSC_EXTERN PetscErrorCode SNESSetJacobianDomainError(SNES);
241 PETSC_EXTERN PetscErrorCode SNESSetCheckJacobianDomainError(SNES, PetscBool);
242 PETSC_EXTERN PetscErrorCode SNESGetCheckJacobianDomainError(SNES, PetscBool *);
243 
244 #define SNES_CONVERGED_TR_DELTA_DEPRECATED SNES_CONVERGED_TR_DELTA PETSC_DEPRECATED_ENUM(3, 12, 0, "SNES_DIVERGED_TR_DELTA", )
245 /*E
246     SNESConvergedReason - reason a `SNESSolve()` was determined to have converged or diverged
247 
248    Values:
249 +  `SNES_CONVERGED_FNORM_ABS`      - 2-norm(F) <= abstol
250 .  `SNES_CONVERGED_FNORM_RELATIVE` - 2-norm(F) <= rtol*2-norm(F(x_0)) where x_0 is the initial guess
251 .  `SNES_CONVERGED_SNORM_RELATIVE` - The 2-norm of the last step <= stol * 2-norm(x) where x is the current
252 .  `SNES_DIVERGED_FUNCTION_COUNT`  - The user provided function has been called more times than the maximum set in `SNESSetTolerances()`
253 .  `SNES_DIVERGED_DTOL`            - The norm of the function has increased by a factor of divtol set with `SNESSetDivergenceTolerance()`
254 .  `SNES_DIVERGED_FNORM_NAN`       - the 2-norm of the current function evaluation is not-a-number (NaN), this
255                                      is usually caused by a division of 0 by 0.
256 .  `SNES_DIVERGED_MAX_IT`          - `SNESSolve()` has reached the maximum number of iterations requested
257 .  `SNES_DIVERGED_LINE_SEARCH`     - The line search has failed. This only occurs for `SNES` solvers that use a line search
258 .  `SNES_DIVERGED_LOCAL_MIN`       - the algorithm seems to have stagnated at a local minimum that is not zero.
259 -  `SNES_CONERGED_ITERATING`       - this only occurs if `SNESGetConvergedReason()` is called during the `SNESSolve()`
260 
261    Level: beginner
262 
263     Notes:
264    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
265    testing with `-pc_type lu` to eliminate the linear solver as the cause of the problem).
266 
267    `SNES_DIVERGED_LOCAL_MIN` can only occur when using the line-search variant of `SNES`.
268    The line search wants to minimize Q(alpha) = 1/2 || F(x + alpha s) ||^2_2  this occurs
269    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
270    you get Q'(alpha) = -F(x)^T F'(x)^(-1)^T F'(x+alpha s)F(x+alpha s); when alpha = 0
271    Q'(0) = - ||F(x)||^2_2 which is always NEGATIVE if F'(x) is invertible. This means the Newton
272    direction is a descent direction and the line search should succeed if alpha is small enough.
273 
274    If F'(x) is NOT invertible AND F'(x)^T F(x) = 0 then Q'(0) = 0 and the Newton direction
275    is NOT a descent direction so the line search will fail. All one can do at this point
276    is change the initial guess and try again.
277 
278    An alternative explanation: Newton's method can be regarded as replacing the function with
279    its linear approximation and minimizing the 2-norm of that. That is F(x+s) approx F(x) + F'(x)s
280    so we minimize || F(x) + F'(x) s ||^2_2; do this using Least Squares. If F'(x) is invertible then
281    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
282    exists a nontrivial (that is F'(x)s != 0) solution to the equation and this direction is
283    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)
284    = - (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
285    and F'(x)^T F'(x) has no negative eigenvalues Q'(0) < 0 so s is a descent direction and the line
286    search should succeed for small enough alpha.
287 
288    Note that this RARELY happens in practice. Far more likely the linear system is not being solved
289    (well enough?) or the Jacobian is wrong.
290 
291    `SNES_DIVERGED_MAX_IT` means that the solver reached the maximum number of iterations without satisfying any
292    convergence criteria. `SNES_CONVERGED_ITS` means that `SNESConvergedSkip()` was chosen as the convergence test;
293    thus the usual convergence criteria have not been checked and may or may not be satisfied.
294 
295 .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `KSPConvergedReason`, `SNESSetConvergenceTest()`, `SNESSetTolerances()`
296 E*/
297 typedef enum {                       /* converged */
298   SNES_CONVERGED_FNORM_ABS      = 2, /* ||F|| < atol */
299   SNES_CONVERGED_FNORM_RELATIVE = 3, /* ||F|| < rtol*||F_initial|| */
300   SNES_CONVERGED_SNORM_RELATIVE = 4, /* Newton computed step size small; || delta x || < stol || x ||*/
301   SNES_CONVERGED_ITS            = 5, /* maximum iterations reached */
302   SNES_BREAKOUT_INNER_ITER      = 6, /* Flag to break out of inner loop after checking custom convergence. */
303                                      /* it is used in multi-phase flow when state changes */
304   /* diverged */
305   SNES_DIVERGED_FUNCTION_DOMAIN      = -1, /* the new x location passed the function is not in the domain of F */
306   SNES_DIVERGED_FUNCTION_COUNT       = -2,
307   SNES_DIVERGED_LINEAR_SOLVE         = -3, /* the linear solve failed */
308   SNES_DIVERGED_FNORM_NAN            = -4,
309   SNES_DIVERGED_MAX_IT               = -5,
310   SNES_DIVERGED_LINE_SEARCH          = -6,  /* the line search failed */
311   SNES_DIVERGED_INNER                = -7,  /* inner solve failed */
312   SNES_DIVERGED_LOCAL_MIN            = -8,  /* || J^T b || is small, implies converged to local minimum of F() */
313   SNES_DIVERGED_DTOL                 = -9,  /* || F || > divtol*||F_initial|| */
314   SNES_DIVERGED_JACOBIAN_DOMAIN      = -10, /* Jacobian calculation does not make sense */
315   SNES_DIVERGED_TR_DELTA             = -11,
316   SNES_CONVERGED_TR_DELTA_DEPRECATED = -11,
317 
318   SNES_CONVERGED_ITERATING = 0
319 } SNESConvergedReason;
320 PETSC_EXTERN const char *const *SNESConvergedReasons;
321 
322 /*MC
323    SNES_CONVERGED_FNORM_ABS - 2-norm(F) <= abstol
324 
325    Level: beginner
326 
327 .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`
328 M*/
329 
330 /*MC
331    SNES_CONVERGED_FNORM_RELATIVE - 2-norm(F) <= rtol*2-norm(F(x_0)) where x_0 is the initial guess
332 
333    Level: beginner
334 
335 .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`
336 M*/
337 
338 /*MC
339   SNES_CONVERGED_SNORM_RELATIVE - The 2-norm of the last step <= stol * 2-norm(x) where x is the current
340   solution and stol is the 4th argument to `SNESSetTolerances()`
341 
342   Options Database Key:
343   -snes_stol <stol> - the step tolerance
344 
345    Level: beginner
346 
347 .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`
348 M*/
349 
350 /*MC
351    SNES_DIVERGED_FUNCTION_COUNT - The user provided function has been called more times then the final
352    argument to `SNESSetTolerances()`
353 
354    Level: beginner
355 
356 .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`
357 M*/
358 
359 /*MC
360    SNES_DIVERGED_DTOL - The norm of the function has increased by a factor of divtol set with `SNESSetDivergenceTolerance()`
361 
362    Level: beginner
363 
364 .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`, `SNESSetDivergenceTolerance()`
365 M*/
366 
367 /*MC
368    SNES_DIVERGED_FNORM_NAN - the 2-norm of the current function evaluation is not-a-number (NaN), this
369    is usually caused by a division of 0 by 0.
370 
371    Level: beginner
372 
373 .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`
374 M*/
375 
376 /*MC
377    SNES_DIVERGED_MAX_IT - SNESSolve() has reached the maximum number of iterations requested
378 
379    Level: beginner
380 
381 .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`
382 M*/
383 
384 /*MC
385    SNES_DIVERGED_LINE_SEARCH - The line search has failed. This only occurs for a `SNES` solvers that use a line search
386 
387    Level: beginner
388 
389 .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`, `SNESLineSearch`
390 M*/
391 
392 /*MC
393    SNES_DIVERGED_LOCAL_MIN - the algorithm seems to have stagnated at a local minimum that is not zero.
394    See the manual page for `SNESConvergedReason` for more details
395 
396    Level: beginner
397 
398 .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`
399 M*/
400 
401 /*MC
402    SNES_CONERGED_ITERATING - this only occurs if `SNESGetConvergedReason()` is called during the `SNESSolve()`
403 
404    Level: beginner
405 
406 .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`
407 M*/
408 
409 PETSC_EXTERN PetscErrorCode SNESSetConvergenceTest(SNES, PetscErrorCode (*)(SNES, PetscInt, PetscReal, PetscReal, PetscReal, SNESConvergedReason *, void *), void *, PetscErrorCode (*)(void *));
410 PETSC_EXTERN PetscErrorCode SNESConvergedDefault(SNES, PetscInt, PetscReal, PetscReal, PetscReal, SNESConvergedReason *, void *);
411 PETSC_EXTERN PetscErrorCode SNESConvergedSkip(SNES, PetscInt, PetscReal, PetscReal, PetscReal, SNESConvergedReason *, void *);
412 PETSC_EXTERN PetscErrorCode SNESConvergedCorrectPressure(SNES, PetscInt, PetscReal, PetscReal, PetscReal, SNESConvergedReason *, void *);
413 PETSC_EXTERN PetscErrorCode SNESGetConvergedReason(SNES, SNESConvergedReason *);
414 PETSC_EXTERN PetscErrorCode SNESGetConvergedReasonString(SNES, const char **);
415 PETSC_EXTERN PetscErrorCode SNESSetConvergedReason(SNES, SNESConvergedReason);
416 
417 PETSC_DEPRECATED_FUNCTION(3, 5, 0, "SNESConvergedSkip()", ) static inline void SNESSkipConverged(void)
418 { /* never called */
419 }
420 #define SNESSkipConverged (SNESSkipConverged, SNESConvergedSkip)
421 
422 /*S
423   SNESInitialGuessFn - A prototype of a `SNES` compute initial guess function that would be passed to `SNESSetComputeInitialGuess()`
424 
425   Calling Sequence:
426 + snes  - `SNES` context
427 . u   - output vector to contain initial guess
428 - ctx - [optional] user-defined function context
429 
430   Level: beginner
431 
432 .seealso: [](ch_snes), `SNES`, `SNESSetComputeInitialGuess()`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESJacobianFn`, `SNESFunctionFn`
433 S*/
434 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode(SNESInitialGuessFn)(SNES snes, Vec u, void *ctx);
435 
436 /*S
437   SNESFunctionFn - A prototype of a `SNES` evaluation function that would be passed to `SNESSetFunction()`
438 
439   Calling Sequence:
440 + snes  - `SNES` context
441 . u   - input vector
442 . F   - function vector
443 - ctx - [optional] user-defined function context
444 
445   Level: beginner
446 
447 .seealso: [](ch_snes), `SNES`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESJacobianFn`, `SNESNGSFn`
448 S*/
449 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode(SNESFunctionFn)(SNES snes, Vec u, Vec F, void *ctx);
450 
451 /*S
452   SNESObjectiveFn - A prototype of a `SNES` objective evaluation function that would be passed to `SNESSetObjective()`
453 
454   Calling Sequence:
455 + snes  - `SNES` context
456 . u   - input vector
457 . o   - output value
458 - ctx - [optional] user-defined function context
459 
460   Level: beginner
461 
462 .seealso: [](ch_snes), `SNES`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESJacobianFn`, `SNESNGSFn`
463 S*/
464 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode(SNESObjectiveFn)(SNES snes, Vec u, PetscReal *o, void *ctx);
465 
466 /*S
467   SNESJacobianFn - A prototype of a `SNES` Jacobian evaluation function that would be passed to `SNESSetJacobian()`
468 
469   Calling Sequence:
470 + snes   - the `SNES` context obtained from `SNESCreate()`
471 . u    - input vector
472 . Amat - (approximate) Jacobian matrix
473 . Pmat - matrix used to construct the preconditioner, often the same as `Amat`
474 - ctx  - [optional] user-defined context for matrix evaluation routine
475 
476   Level: beginner
477 
478 .seealso: [](ch_snes), `SNES`, `SNESSetJacobian()`, `SNESGetJacobian()`, `SNESFunctionFn`, `SNESNGSFn`
479 S*/
480 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode(SNESJacobianFn)(SNES snes, Vec u, Mat Amat, Mat Pmat, void *ctx);
481 
482 /*S
483   SNESNGSFn - A prototype of a `SNES` nonlinear Gauss-Seidel function that would be passed to `SNESSetNGS()`
484 
485   Calling Sequence:
486 + snes   - the `SNES` context obtained from `SNESCreate()`
487 . u    - the current solution, updated in place
488 . b    - the right-hand side vector (which may be `NULL`)
489 - ctx  - [optional] user-defined context for matrix evaluation routine
490 
491   Level: beginner
492 
493 .seealso: [](ch_snes), `SNES`, `SNESSetJacobian()`, `SNESGetJacobian()`, `SNESFunctionFn`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESJacobianFn`
494 S*/
495 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode(SNESNGSFn)(SNES snes, Vec u, Vec b, void *ctx);
496 
497 /*S
498   SNESUpdateFn - A prototype of a `SNES` update function that would be passed to `SNESSetUpdate()`
499 
500   Calling Sequence:
501 + snes - `SNES` context
502 - step - the current iteration index
503 
504   Level: advanced
505 
506 .seealso: [](ch_snes), `SNES`, `SNESSetUpdate()`
507 S*/
508 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode(SNESUpdateFn)(SNES snes, PetscInt step);
509 
510 /* --------- Solving systems of nonlinear equations --------------- */
511 PETSC_EXTERN PetscErrorCode SNESSetFunction(SNES, Vec, SNESFunctionFn *, void *);
512 PETSC_EXTERN PetscErrorCode SNESGetFunction(SNES, Vec *, SNESFunctionFn **, void **);
513 PETSC_EXTERN PetscErrorCode SNESComputeFunction(SNES, Vec, Vec);
514 PETSC_EXTERN PetscErrorCode SNESComputeMFFunction(SNES, Vec, Vec);
515 PETSC_EXTERN PetscErrorCode SNESSetInitialFunction(SNES, Vec);
516 
517 PETSC_EXTERN PetscErrorCode SNESSetJacobian(SNES, Mat, Mat, SNESJacobianFn *, void *);
518 PETSC_EXTERN PetscErrorCode SNESGetJacobian(SNES, Mat *, Mat *, SNESJacobianFn **, void **);
519 PETSC_EXTERN SNESFunctionFn SNESObjectiveComputeFunctionDefaultFD;
520 PETSC_EXTERN SNESJacobianFn SNESComputeJacobianDefault;
521 PETSC_EXTERN SNESJacobianFn SNESComputeJacobianDefaultColor;
522 PETSC_EXTERN PetscErrorCode SNESPruneJacobianColor(SNES, Mat, Mat);
523 PETSC_EXTERN PetscErrorCode SNESSetComputeInitialGuess(SNES, SNESInitialGuessFn *, void *);
524 PETSC_EXTERN PetscErrorCode SNESSetPicard(SNES, Vec, SNESFunctionFn *, Mat, Mat, SNESJacobianFn *, void *);
525 PETSC_EXTERN PetscErrorCode SNESGetPicard(SNES, Vec *, SNESFunctionFn **, Mat *, Mat *, SNESJacobianFn **, void **);
526 PETSC_EXTERN SNESFunctionFn SNESPicardComputeFunction;
527 PETSC_EXTERN SNESFunctionFn SNESPicardComputeMFFunction;
528 PETSC_EXTERN SNESJacobianFn SNESPicardComputeJacobian;
529 
530 PETSC_EXTERN PetscErrorCode SNESSetObjective(SNES, SNESObjectiveFn *, void *);
531 PETSC_EXTERN PetscErrorCode SNESGetObjective(SNES, SNESObjectiveFn **, void **);
532 PETSC_EXTERN PetscErrorCode SNESComputeObjective(SNES, Vec, PetscReal *);
533 
534 PETSC_EXTERN PetscErrorCode SNESSetUpdate(SNES, SNESUpdateFn *);
535 
536 /*E
537    SNESNormSchedule - Frequency with which the norm is computed during a nonliner solve
538 
539    Values:
540 +   `SNES_NORM_DEFAULT`            - use the default behavior for the current `SNESType`
541 .   `SNES_NORM_NONE`               - avoid all norm computations
542 .   `SNES_NORM_ALWAYS`             - compute the norms whenever possible
543 .   `SNES_NORM_INITIAL_ONLY`       - compute the norm only when the algorithm starts
544 .   `SNES_NORM_FINAL_ONLY`         - compute the norm only when the algorithm finishes
545 -   `SNES_NORM_INITIAL_FINAL_ONLY` - compute the norm at the start and end of the algorithm
546 
547    Level: advanced
548 
549    Notes:
550    Support for these is highly dependent on the solver.
551 
552    Some options limit the convergence tests that can be used.
553 
554    The `SNES_NORM_NONE` option is most commonly used when the nonlinear solver is being used as a smoother, for example for `SNESFAS`
555 
556    This is primarily used to turn off extra norm and function computation
557    when the solvers are composed.
558 
559 .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `KSPSetNormType()`,
560           `KSPSetConvergenceTest()`, `KSPSetPCSide()`
561 E*/
562 typedef enum {
563   SNES_NORM_DEFAULT            = -1,
564   SNES_NORM_NONE               = 0,
565   SNES_NORM_ALWAYS             = 1,
566   SNES_NORM_INITIAL_ONLY       = 2,
567   SNES_NORM_FINAL_ONLY         = 3,
568   SNES_NORM_INITIAL_FINAL_ONLY = 4
569 } SNESNormSchedule;
570 PETSC_EXTERN const char *const *const SNESNormSchedules;
571 
572 /*MC
573    SNES_NORM_NONE - Don't compute function and its L2 norm when possible
574 
575    Level: advanced
576 
577    Note:
578    This is most useful for stationary solvers with a fixed number of iterations used as smoothers.
579 
580 .seealso: [](ch_snes), `SNESNormSchedule`, `SNES`, `SNESSetNormSchedule()`, `SNES_NORM_DEFAULT`
581 M*/
582 
583 /*MC
584    SNES_NORM_ALWAYS - Compute the function and its L2 norm at each iteration.
585 
586    Level: advanced
587 
588    Note:
589    Most solvers will use this no matter what norm type is passed to them.
590 
591 .seealso: [](ch_snes), `SNESNormSchedule`, `SNES`, `SNESSetNormSchedule()`, `SNES_NORM_NONE`
592 M*/
593 
594 /*MC
595    SNES_NORM_INITIAL_ONLY - Compute the function and its L2 at iteration 0, but do not update it.
596 
597    Level: advanced
598 
599    Notes:
600    This method is useful in composed methods, when a true solution might actually be found before `SNESSolve()` is called.
601    This option enables the solve to abort on the zeroth iteration if this is the case.
602 
603    For solvers that require the computation of the L2 norm of the function as part of the method, this merely cancels
604    the norm computation at the last iteration (if possible).
605 
606 .seealso: [](ch_snes), `SNESNormSchedule`, `SNES`, `SNESSetNormSchedule()`, `SNES_NORM_FINAL_ONLY`, `SNES_NORM_INITIAL_FINAL_ONLY`
607 M*/
608 
609 /*MC
610    SNES_NORM_FINAL_ONLY - Compute the function and its L2 norm on only the final iteration.
611 
612    Level: advanced
613 
614    Note:
615    For solvers that require the computation of the L2 norm of the function as part of the method, behaves
616    exactly as `SNES_NORM_DEFAULT`.  This method is useful when the function is gotten after `SNESSolve()` and
617    used in subsequent computation for methods that do not need the norm computed during the rest of the
618    solution procedure.
619 
620 .seealso: [](ch_snes), `SNESNormSchedule`, `SNES`, `SNESSetNormSchedule()`, `SNES_NORM_INITIAL_ONLY`, `SNES_NORM_INITIAL_FINAL_ONLY`
621 M*/
622 
623 /*MC
624    SNES_NORM_INITIAL_FINAL_ONLY - Compute the function and its L2 norm on only the initial and final iterations.
625 
626    Level: advanced
627 
628    Note:
629    This method combines the benefits of `SNES_NORM_INITIAL_ONLY` and `SNES_NORM_FINAL_ONLY`.
630 
631 .seealso: [](ch_snes), `SNESNormSchedule`, `SNES`, `SNESSetNormSchedule()`, `SNES_NORM_SNES_NORM_INITIAL_ONLY`, `SNES_NORM_FINAL_ONLY`
632 M*/
633 
634 PETSC_EXTERN PetscErrorCode SNESSetNormSchedule(SNES, SNESNormSchedule);
635 PETSC_EXTERN PetscErrorCode SNESGetNormSchedule(SNES, SNESNormSchedule *);
636 PETSC_EXTERN PetscErrorCode SNESSetFunctionNorm(SNES, PetscReal);
637 PETSC_EXTERN PetscErrorCode SNESGetFunctionNorm(SNES, PetscReal *);
638 PETSC_EXTERN PetscErrorCode SNESGetUpdateNorm(SNES, PetscReal *);
639 PETSC_EXTERN PetscErrorCode SNESGetSolutionNorm(SNES, PetscReal *);
640 
641 /*E
642    SNESFunctionType - Type of function computed
643 
644    Values:
645 +  `SNES_FUNCTION_DEFAULT`          - the default behavior for the current `SNESType`
646 .  `SNES_FUNCTION_UNPRECONDITIONED` - the original function provided
647 -  `SNES_FUNCTION_PRECONDITIONED`   - the modification of the function by the preconditioner
648 
649    Level: advanced
650 
651    Note:
652    Support for these is dependent on the solver.
653 
654 .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `KSPSetNormType()`,
655           `KSPSetConvergenceTest()`, `KSPSetPCSide()`
656 E*/
657 typedef enum {
658   SNES_FUNCTION_DEFAULT          = -1,
659   SNES_FUNCTION_UNPRECONDITIONED = 0,
660   SNES_FUNCTION_PRECONDITIONED   = 1
661 } SNESFunctionType;
662 PETSC_EXTERN const char *const *const SNESFunctionTypes;
663 
664 PETSC_EXTERN PetscErrorCode SNESSetFunctionType(SNES, SNESFunctionType);
665 PETSC_EXTERN PetscErrorCode SNESGetFunctionType(SNES, SNESFunctionType *);
666 
667 PETSC_EXTERN PetscErrorCode SNESSetNGS(SNES, SNESNGSFn *, void *);
668 PETSC_EXTERN PetscErrorCode SNESGetNGS(SNES, SNESNGSFn **, void **);
669 PETSC_EXTERN PetscErrorCode SNESComputeNGS(SNES, Vec, Vec);
670 
671 PETSC_EXTERN PetscErrorCode SNESNGSSetSweeps(SNES, PetscInt);
672 PETSC_EXTERN PetscErrorCode SNESNGSGetSweeps(SNES, PetscInt *);
673 PETSC_EXTERN PetscErrorCode SNESNGSSetTolerances(SNES, PetscReal, PetscReal, PetscReal, PetscInt);
674 PETSC_EXTERN PetscErrorCode SNESNGSGetTolerances(SNES, PetscReal *, PetscReal *, PetscReal *, PetscInt *);
675 
676 PETSC_EXTERN PetscErrorCode SNESSetAlwaysComputesFinalResidual(SNES, PetscBool);
677 PETSC_EXTERN PetscErrorCode SNESGetAlwaysComputesFinalResidual(SNES, PetscBool *);
678 
679 PETSC_EXTERN PetscErrorCode SNESShellGetContext(SNES, void *);
680 PETSC_EXTERN PetscErrorCode SNESShellSetContext(SNES, void *);
681 PETSC_EXTERN PetscErrorCode SNESShellSetSolve(SNES, PetscErrorCode (*)(SNES, Vec));
682 
683 /* --------- Routines specifically for line search methods --------------- */
684 
685 /*S
686    SNESLineSearch - Abstract PETSc object that manages line-search operations for nonlinear solvers
687 
688    Level: beginner
689 
690 .seealso: [](ch_snes), `SNESLineSearchType`, `SNESLineSearchCreate()`, `SNESLineSearchSetType()`, `SNES`
691 S*/
692 typedef struct _p_LineSearch *SNESLineSearch;
693 
694 /*J
695    SNESLineSearchType - String with the name of a PETSc line search method `SNESLineSearch`
696 
697    Values:
698 +  `SNESLINESEARCHBASIC`   - (or equivalently `SNESLINESEARCHNONE`) Simple damping line search, defaults to using the full Newton step
699 .  `SNESLINESEARCHBT`      - Backtracking line search over the L2 norm of the function
700 .  `SNESLINESEARCHL2`      - Secant line search over the L2 norm of the function
701 .  `SNESLINESEARCHCP`      - Critical point secant line search assuming F(x) = grad G(x) for some unknown G(x)
702 .  `SNESLINESEARCHNLEQERR` - Affine-covariant error-oriented linesearch
703 -  `SNESLINESEARCHSHELL`   - User provided `SNESLineSearch` implementation
704 
705    Level: beginner
706 
707 .seealso: [](ch_snes), `SNESLineSearch`, `SNESLineSearchSetType()`, `SNES`
708 J*/
709 typedef const char *SNESLineSearchType;
710 #define SNESLINESEARCHBT        "bt"
711 #define SNESLINESEARCHNLEQERR   "nleqerr"
712 #define SNESLINESEARCHBASIC     "basic"
713 #define SNESLINESEARCHNONE      "none"
714 #define SNESLINESEARCHL2        "l2"
715 #define SNESLINESEARCHCP        "cp"
716 #define SNESLINESEARCHSHELL     "shell"
717 #define SNESLINESEARCHNCGLINEAR "ncglinear"
718 
719 PETSC_EXTERN PetscFunctionList SNESList;
720 PETSC_EXTERN PetscClassId      SNESLINESEARCH_CLASSID;
721 PETSC_EXTERN PetscFunctionList SNESLineSearchList;
722 
723 #define SNES_LINESEARCH_ORDER_LINEAR    1
724 #define SNES_LINESEARCH_ORDER_QUADRATIC 2
725 #define SNES_LINESEARCH_ORDER_CUBIC     3
726 
727 /*S
728   SNESLineSearchVIProjectFn - A prototype of a `SNES` function that projects a vector onto the VI bounds, passed to `SNESLineSearchSetVIFunctions()`
729 
730   Calling Sequence:
731 + snes  - `SNES` context
732 - u     - the vector to project to the bounds
733 
734   Level: advanced
735 
736   Note:
737   The deprecated `SNESLineSearchVIProjectFunc` still works as a replacement for `SNESLineSearchVIProjectFn` *.
738 
739 .seealso: [](ch_snes), `SNES`, `SNESLineSearch`
740 S*/
741 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode(SNESLineSearchVIProjectFn)(SNES snes, Vec u);
742 PETSC_EXTERN_TYPEDEF typedef SNESLineSearchVIProjectFn *SNESLineSearchVIProjectFunc; // deprecated
743 
744 /*S
745   SNESLineSearchVIProjectFn - A prototype of a `SNES` function that computes the norm of the active set variables in a vector in a VI solve,
746   passed to `SNESLineSearchSetVIFunctions()`
747 
748   Calling Sequence:
749 + snes  - `SNES` context
750 . f     - the vector to compute the norm of
751 . u     - the current solution, entries that are on the VI bounds are ignored
752 - fnorm - the resulting norm
753 
754   Level: advanced
755 
756   Note:
757   The deprecated `SNESLineSearchVINormFunc` still works as a replacement for `SNESLineSearchVINormFn` *.
758 
759 .seealso: [](ch_snes), `SNES`, `SNESLineSearch`
760 S*/
761 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode(SNESLineSearchVINormFn)(SNES snes, Vec f, Vec u, PetscReal *fnorm);
762 PETSC_EXTERN_TYPEDEF typedef SNESLineSearchVINormFn *SNESLineSearchVINormFunc; // deprecated
763 
764 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode(SNESLineSearchApplyFn)(SNESLineSearch);
765 PETSC_EXTERN_TYPEDEF typedef SNESLineSearchApplyFn *SNESLineSearchApplyFunc; // deprecated
766 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode(SNESLineSearchShellApplyFn)(SNESLineSearch, void *);
767 PETSC_EXTERN_TYPEDEF typedef SNESLineSearchShellApplyFn *SNESLineSearchUserFunc; // deprecated
768 
769 PETSC_EXTERN PetscErrorCode SNESLineSearchCreate(MPI_Comm, SNESLineSearch *);
770 PETSC_EXTERN PetscErrorCode SNESLineSearchReset(SNESLineSearch);
771 PETSC_EXTERN PetscErrorCode SNESLineSearchView(SNESLineSearch, PetscViewer);
772 PETSC_EXTERN PetscErrorCode SNESLineSearchDestroy(SNESLineSearch *);
773 PETSC_EXTERN PetscErrorCode SNESLineSearchGetType(SNESLineSearch, SNESLineSearchType *);
774 PETSC_EXTERN PetscErrorCode SNESLineSearchSetType(SNESLineSearch, SNESLineSearchType);
775 PETSC_EXTERN PetscErrorCode SNESLineSearchSetFromOptions(SNESLineSearch);
776 PETSC_EXTERN PetscErrorCode SNESLineSearchSetFunction(SNESLineSearch, PetscErrorCode (*)(SNES, Vec, Vec));
777 PETSC_EXTERN PetscErrorCode SNESLineSearchSetUp(SNESLineSearch);
778 PETSC_EXTERN PetscErrorCode SNESLineSearchApply(SNESLineSearch, Vec, Vec, PetscReal *, Vec);
779 PETSC_EXTERN PetscErrorCode SNESLineSearchPreCheck(SNESLineSearch, Vec, Vec, PetscBool *);
780 PETSC_EXTERN PetscErrorCode SNESLineSearchPostCheck(SNESLineSearch, Vec, Vec, Vec, PetscBool *, PetscBool *);
781 PETSC_EXTERN PetscErrorCode SNESLineSearchSetWorkVecs(SNESLineSearch, PetscInt);
782 
783 /* set the functions for precheck and postcheck */
784 
785 PETSC_EXTERN PetscErrorCode SNESLineSearchSetPreCheck(SNESLineSearch, PetscErrorCode (*)(SNESLineSearch, Vec, Vec, PetscBool *, void *), void *ctx);
786 PETSC_EXTERN PetscErrorCode SNESLineSearchSetPostCheck(SNESLineSearch, PetscErrorCode (*)(SNESLineSearch, Vec, Vec, Vec, PetscBool *, PetscBool *, void *), void *ctx);
787 
788 PETSC_EXTERN PetscErrorCode SNESLineSearchGetPreCheck(SNESLineSearch, PetscErrorCode (**)(SNESLineSearch, Vec, Vec, PetscBool *, void *), void **ctx);
789 PETSC_EXTERN PetscErrorCode SNESLineSearchGetPostCheck(SNESLineSearch, PetscErrorCode (**)(SNESLineSearch, Vec, Vec, Vec, PetscBool *, PetscBool *, void *), void **ctx);
790 
791 /* set the functions for VI-specific line search operations */
792 
793 PETSC_EXTERN PetscErrorCode SNESLineSearchSetVIFunctions(SNESLineSearch, SNESLineSearchVIProjectFn *, SNESLineSearchVINormFn *);
794 PETSC_EXTERN PetscErrorCode SNESLineSearchGetVIFunctions(SNESLineSearch, SNESLineSearchVIProjectFn **, SNESLineSearchVINormFn **);
795 
796 /* pointers to the associated SNES in order to be able to get the function evaluation out */
797 PETSC_EXTERN PetscErrorCode SNESLineSearchSetSNES(SNESLineSearch, SNES);
798 PETSC_EXTERN PetscErrorCode SNESLineSearchGetSNES(SNESLineSearch, SNES *);
799 
800 /* set and get the parameters and vectors */
801 PETSC_EXTERN PetscErrorCode SNESLineSearchGetTolerances(SNESLineSearch, PetscReal *, PetscReal *, PetscReal *, PetscReal *, PetscReal *, PetscInt *);
802 PETSC_EXTERN PetscErrorCode SNESLineSearchSetTolerances(SNESLineSearch, PetscReal, PetscReal, PetscReal, PetscReal, PetscReal, PetscInt);
803 
804 PETSC_EXTERN PetscErrorCode SNESLineSearchPreCheckPicard(SNESLineSearch, Vec, Vec, PetscBool *, void *);
805 
806 PETSC_EXTERN PetscErrorCode SNESLineSearchGetLambda(SNESLineSearch, PetscReal *);
807 PETSC_EXTERN PetscErrorCode SNESLineSearchSetLambda(SNESLineSearch, PetscReal);
808 
809 PETSC_EXTERN PetscErrorCode SNESLineSearchGetDamping(SNESLineSearch, PetscReal *);
810 PETSC_EXTERN PetscErrorCode SNESLineSearchSetDamping(SNESLineSearch, PetscReal);
811 
812 PETSC_EXTERN PetscErrorCode SNESLineSearchGetOrder(SNESLineSearch, PetscInt *order);
813 PETSC_EXTERN PetscErrorCode SNESLineSearchSetOrder(SNESLineSearch, PetscInt order);
814 
815 /*E
816     SNESLineSearchReason - indication if the line search has succeeded or failed and why
817 
818   Values:
819 +  `SNES_LINESEARCH_SUCCEEDED`       - the line search succeeded
820 .  `SNES_LINESEARCH_FAILED_NANORINF` - a not a number of infinity appeared in the computions
821 .  `SNES_LINESEARCH_FAILED_DOMAIN`   - the function was evaluated outside of its domain, see `SNESSetFunctionDomainError()` and `SNESSetJacobianDomainError()`
822 .  `SNES_LINESEARCH_FAILED_REDUCT`   - the linear search failed to get the requested decrease in its norm or objective
823 .  `SNES_LINESEARCH_FAILED_USER`     - used by `SNESLINESEARCHNLEQERR` to indicate the user changed the search direction inappropriately
824 -  `SNES_LINESEARCH_FAILED_FUNCTION` - indicates the maximum number of function evaluations allowed has been surpassed, `SNESConvergedReason` is also
825                                        set to `SNES_DIVERGED_FUNCTION_COUNT`
826 
827    Level: intermediate
828 
829    Developer Note:
830    Some of these reasons overlap with values of `SNESConvergedReason`
831 
832 .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `KSPConvergedReason`, `SNESSetConvergenceTest()`,
833           `SNESSetFunctionDomainError()` and `SNESSetJacobianDomainError()`
834 E*/
835 typedef enum {
836   SNES_LINESEARCH_SUCCEEDED,
837   SNES_LINESEARCH_FAILED_NANORINF,
838   SNES_LINESEARCH_FAILED_DOMAIN,
839   SNES_LINESEARCH_FAILED_REDUCT, /* INSUFFICIENT REDUCTION */
840   SNES_LINESEARCH_FAILED_USER,
841   SNES_LINESEARCH_FAILED_FUNCTION
842 } SNESLineSearchReason;
843 
844 PETSC_EXTERN PetscErrorCode SNESLineSearchGetReason(SNESLineSearch, SNESLineSearchReason *);
845 PETSC_EXTERN PetscErrorCode SNESLineSearchSetReason(SNESLineSearch, SNESLineSearchReason);
846 
847 PETSC_EXTERN PetscErrorCode SNESLineSearchGetVecs(SNESLineSearch, Vec *, Vec *, Vec *, Vec *, Vec *);
848 PETSC_EXTERN PetscErrorCode SNESLineSearchSetVecs(SNESLineSearch, Vec, Vec, Vec, Vec, Vec);
849 
850 PETSC_EXTERN PetscErrorCode SNESLineSearchGetNorms(SNESLineSearch, PetscReal *, PetscReal *, PetscReal *);
851 PETSC_EXTERN PetscErrorCode SNESLineSearchSetNorms(SNESLineSearch, PetscReal, PetscReal, PetscReal);
852 PETSC_EXTERN PetscErrorCode SNESLineSearchComputeNorms(SNESLineSearch);
853 PETSC_EXTERN PetscErrorCode SNESLineSearchSetComputeNorms(SNESLineSearch, PetscBool);
854 
855 PETSC_EXTERN PetscErrorCode SNESLineSearchMonitor(SNESLineSearch);
856 PETSC_EXTERN PetscErrorCode SNESLineSearchMonitorSet(SNESLineSearch, PetscErrorCode (*)(SNESLineSearch, void *), void *, PetscErrorCode (*)(void **));
857 PETSC_EXTERN PetscErrorCode SNESLineSearchMonitorSetFromOptions(SNESLineSearch, const char[], const char[], const char[], PetscErrorCode (*)(SNESLineSearch, PetscViewerAndFormat *), PetscErrorCode (*)(SNESLineSearch, PetscViewerAndFormat *));
858 PETSC_EXTERN PetscErrorCode SNESLineSearchMonitorCancel(SNESLineSearch);
859 PETSC_EXTERN PetscErrorCode SNESLineSearchSetDefaultMonitor(SNESLineSearch, PetscViewer);
860 PETSC_EXTERN PetscErrorCode SNESLineSearchGetDefaultMonitor(SNESLineSearch, PetscViewer *);
861 PETSC_EXTERN PetscErrorCode SNESLineSearchMonitorSolutionUpdate(SNESLineSearch, PetscViewerAndFormat *);
862 
863 PETSC_EXTERN PetscErrorCode SNESLineSearchAppendOptionsPrefix(SNESLineSearch, const char prefix[]);
864 PETSC_EXTERN PetscErrorCode SNESLineSearchGetOptionsPrefix(SNESLineSearch, const char *prefix[]);
865 
866 /* Shell interface functions */
867 PETSC_EXTERN PetscErrorCode SNESLineSearchShellSetApply(SNESLineSearch, SNESLineSearchShellApplyFn, void *);
868 PETSC_EXTERN PetscErrorCode SNESLineSearchShellGetApply(SNESLineSearch, SNESLineSearchShellApplyFn **, void **);
869 
870 PETSC_DEPRECATED_FUNCTION(3, 21, 0, "SNESLinesearchShellSetApply()", ) static inline PetscErrorCode SNESLineSearchShellSetUserFunc(SNESLineSearch ls, SNESLineSearchUserFunc f, void *ctx)
871 {
872   return SNESLineSearchShellSetApply(ls, f, ctx);
873 }
874 
875 PETSC_DEPRECATED_FUNCTION(3, 21, 0, "SNESLinesearchShellGetApply()", ) static inline PetscErrorCode SNESLineSearchShellGetUserFunc(SNESLineSearch ls, SNESLineSearchUserFunc *f, void **ctx)
876 {
877   return SNESLineSearchShellGetApply(ls, f, ctx);
878 }
879 
880 /* BT interface functions */
881 PETSC_EXTERN PetscErrorCode SNESLineSearchBTSetAlpha(SNESLineSearch, PetscReal);
882 PETSC_EXTERN PetscErrorCode SNESLineSearchBTGetAlpha(SNESLineSearch, PetscReal *);
883 
884 /*register line search types */
885 PETSC_EXTERN PetscErrorCode SNESLineSearchRegister(const char[], PetscErrorCode (*)(SNESLineSearch));
886 
887 /* Routines for VI solver */
888 PETSC_EXTERN PetscErrorCode SNESVISetVariableBounds(SNES, Vec, Vec);
889 PETSC_EXTERN PetscErrorCode SNESVIGetVariableBounds(SNES, Vec *, Vec *);
890 PETSC_EXTERN PetscErrorCode SNESVISetComputeVariableBounds(SNES, PetscErrorCode (*)(SNES, Vec, Vec));
891 PETSC_EXTERN PetscErrorCode SNESVIGetInactiveSet(SNES, IS *);
892 PETSC_EXTERN PetscErrorCode SNESVIGetActiveSetIS(SNES, Vec, Vec, IS *);
893 PETSC_EXTERN PetscErrorCode SNESVIComputeInactiveSetFnorm(SNES, Vec, Vec, PetscReal *);
894 PETSC_EXTERN PetscErrorCode SNESVISetRedundancyCheck(SNES, PetscErrorCode (*)(SNES, IS, IS *, void *), void *);
895 PETSC_EXTERN PetscErrorCode SNESVIComputeMeritFunction(Vec, PetscReal *, PetscReal *);
896 PETSC_EXTERN PetscErrorCode SNESVIComputeFunction(SNES, Vec, Vec, void *);
897 PETSC_EXTERN PetscErrorCode DMSetVI(DM, IS);
898 PETSC_EXTERN PetscErrorCode DMDestroyVI(DM);
899 
900 PETSC_EXTERN PetscErrorCode SNESTestLocalMin(SNES);
901 
902 /* Should this routine be private? */
903 PETSC_EXTERN PetscErrorCode SNESComputeJacobian(SNES, Vec, Mat, Mat);
904 PETSC_EXTERN PetscErrorCode SNESTestJacobian(SNES);
905 PETSC_EXTERN PetscErrorCode SNESTestFunction(SNES);
906 
907 PETSC_EXTERN PetscErrorCode SNESSetDM(SNES, DM);
908 PETSC_EXTERN PetscErrorCode SNESGetDM(SNES, DM *);
909 PETSC_EXTERN PetscErrorCode SNESSetNPC(SNES, SNES);
910 PETSC_EXTERN PetscErrorCode SNESGetNPC(SNES, SNES *);
911 PETSC_EXTERN PetscErrorCode SNESHasNPC(SNES, PetscBool *);
912 PETSC_EXTERN PetscErrorCode SNESApplyNPC(SNES, Vec, Vec, Vec);
913 PETSC_EXTERN PetscErrorCode SNESGetNPCFunction(SNES, Vec, PetscReal *);
914 PETSC_EXTERN PetscErrorCode SNESComputeFunctionDefaultNPC(SNES, Vec, Vec);
915 PETSC_EXTERN PetscErrorCode SNESSetNPCSide(SNES, PCSide);
916 PETSC_EXTERN PetscErrorCode SNESGetNPCSide(SNES, PCSide *);
917 PETSC_EXTERN PetscErrorCode SNESSetLineSearch(SNES, SNESLineSearch);
918 PETSC_EXTERN PetscErrorCode SNESGetLineSearch(SNES, SNESLineSearch *);
919 
920 PETSC_DEPRECATED_FUNCTION(3, 4, 0, "SNESGetLineSearch()", ) static inline PetscErrorCode SNESGetSNESLineSearch(SNES snes, SNESLineSearch *ls)
921 {
922   return SNESGetLineSearch(snes, ls);
923 }
924 PETSC_DEPRECATED_FUNCTION(3, 4, 0, "SNESSetLineSearch()", ) static inline PetscErrorCode SNESSetSNESLineSearch(SNES snes, SNESLineSearch ls)
925 {
926   return SNESSetLineSearch(snes, ls);
927 }
928 
929 PETSC_EXTERN PetscErrorCode SNESSetUpMatrices(SNES);
930 PETSC_EXTERN PetscErrorCode DMSNESSetFunction(DM, SNESFunctionFn *, void *);
931 PETSC_EXTERN PetscErrorCode DMSNESGetFunction(DM, SNESFunctionFn **, void **);
932 PETSC_EXTERN PetscErrorCode DMSNESSetFunctionContextDestroy(DM, PetscErrorCode (*)(void *));
933 PETSC_EXTERN PetscErrorCode DMSNESSetMFFunction(DM, SNESFunctionFn *, void *);
934 PETSC_EXTERN PetscErrorCode DMSNESSetNGS(DM, SNESNGSFn *, void *);
935 PETSC_EXTERN PetscErrorCode DMSNESGetNGS(DM, SNESNGSFn **, void **);
936 PETSC_EXTERN PetscErrorCode DMSNESSetJacobian(DM, SNESJacobianFn *, void *);
937 PETSC_EXTERN PetscErrorCode DMSNESGetJacobian(DM, SNESJacobianFn **, void **);
938 PETSC_EXTERN PetscErrorCode DMSNESSetJacobianContextDestroy(DM, PetscErrorCode (*)(void *));
939 PETSC_EXTERN PetscErrorCode DMSNESSetPicard(DM, SNESFunctionFn *, SNESJacobianFn *, void *);
940 PETSC_EXTERN PetscErrorCode DMSNESGetPicard(DM, SNESFunctionFn **, SNESJacobianFn **, void **);
941 PETSC_EXTERN PetscErrorCode DMSNESSetObjective(DM, SNESObjectiveFn *, void *);
942 PETSC_EXTERN PetscErrorCode DMSNESGetObjective(DM, SNESObjectiveFn **, void **);
943 PETSC_EXTERN PetscErrorCode DMCopyDMSNES(DM, DM);
944 
945 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode(DMDASNESFunctionFn)(DMDALocalInfo *, void *, void *, void *);
946 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode(DMDASNESJacobianFn)(DMDALocalInfo *, void *, Mat, Mat, void *);
947 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode(DMDASNESObjectiveFn)(DMDALocalInfo *, void *, PetscReal *, void *);
948 
949 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode(DMDASNESFunctionVecFn)(DMDALocalInfo *, Vec, Vec, void *);
950 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode(DMDASNESJacobianVecFn)(DMDALocalInfo *, Vec, Mat, Mat, void *);
951 PETSC_EXTERN_TYPEDEF typedef PetscErrorCode(DMDASNESObjectiveVecFn)(DMDALocalInfo *, Vec, PetscReal *, void *);
952 
953 PETSC_EXTERN PetscErrorCode DMDASNESSetFunctionLocal(DM, InsertMode, DMDASNESFunctionFn *, void *);
954 PETSC_EXTERN PetscErrorCode DMDASNESSetJacobianLocal(DM, DMDASNESJacobianFn *, void *);
955 PETSC_EXTERN PetscErrorCode DMDASNESSetObjectiveLocal(DM, DMDASNESObjectiveFn *, void *);
956 PETSC_EXTERN PetscErrorCode DMDASNESSetPicardLocal(DM, InsertMode, DMDASNESFunctionFn *, DMDASNESJacobianFn, void *);
957 
958 PETSC_EXTERN PetscErrorCode DMDASNESSetFunctionLocalVec(DM, InsertMode, DMDASNESFunctionVecFn *, void *);
959 PETSC_EXTERN PetscErrorCode DMDASNESSetJacobianLocalVec(DM, DMDASNESJacobianVecFn *, void *);
960 PETSC_EXTERN PetscErrorCode DMDASNESSetObjectiveLocalVec(DM, DMDASNESObjectiveVecFn *, void *);
961 
962 PETSC_EXTERN PetscErrorCode DMSNESSetBoundaryLocal(DM, PetscErrorCode (*)(DM, Vec, void *), void *);
963 PETSC_EXTERN PetscErrorCode DMSNESSetObjectiveLocal(DM, PetscErrorCode (*)(DM, Vec, PetscReal *, void *), void *);
964 PETSC_EXTERN PetscErrorCode DMSNESSetFunctionLocal(DM, PetscErrorCode (*)(DM, Vec, Vec, void *), void *);
965 PETSC_EXTERN PetscErrorCode DMSNESSetJacobianLocal(DM, PetscErrorCode (*)(DM, Vec, Mat, Mat, void *), void *);
966 PETSC_EXTERN PetscErrorCode DMSNESGetBoundaryLocal(DM, PetscErrorCode (**)(DM, Vec, void *), void **);
967 PETSC_EXTERN PetscErrorCode DMSNESGetObjectiveLocal(DM, PetscErrorCode (**)(DM, Vec, PetscReal *, void *), void **);
968 PETSC_EXTERN PetscErrorCode DMSNESGetFunctionLocal(DM, PetscErrorCode (**)(DM, Vec, Vec, void *), void **);
969 PETSC_EXTERN PetscErrorCode DMSNESGetJacobianLocal(DM, PetscErrorCode (**)(DM, Vec, Mat, Mat, void *), void **);
970 
971 /* Routines for Multiblock solver */
972 PETSC_EXTERN PetscErrorCode SNESMultiblockSetFields(SNES, const char[], PetscInt, const PetscInt *);
973 PETSC_EXTERN PetscErrorCode SNESMultiblockSetIS(SNES, const char[], IS);
974 PETSC_EXTERN PetscErrorCode SNESMultiblockSetBlockSize(SNES, PetscInt);
975 PETSC_EXTERN PetscErrorCode SNESMultiblockSetType(SNES, PCCompositeType);
976 PETSC_EXTERN PetscErrorCode SNESMultiblockGetSubSNES(SNES, PetscInt *, SNES *[]);
977 
978 /*J
979    SNESMSType - String with the name of a PETSc `SNESMS` method.
980 
981    Level: intermediate
982 
983 .seealso: [](ch_snes), `SNESMS`, `SNESMSGetType()`, `SNESMSSetType()`, `SNES`
984 J*/
985 typedef const char *SNESMSType;
986 #define SNESMSM62       "m62"
987 #define SNESMSEULER     "euler"
988 #define SNESMSJAMESON83 "jameson83"
989 #define SNESMSVLTP11    "vltp11"
990 #define SNESMSVLTP21    "vltp21"
991 #define SNESMSVLTP31    "vltp31"
992 #define SNESMSVLTP41    "vltp41"
993 #define SNESMSVLTP51    "vltp51"
994 #define SNESMSVLTP61    "vltp61"
995 
996 PETSC_EXTERN PetscErrorCode SNESMSRegister(SNESMSType, PetscInt, PetscInt, PetscReal, const PetscReal[], const PetscReal[], const PetscReal[]);
997 PETSC_EXTERN PetscErrorCode SNESMSRegisterAll(void);
998 PETSC_EXTERN PetscErrorCode SNESMSGetType(SNES, SNESMSType *);
999 PETSC_EXTERN PetscErrorCode SNESMSSetType(SNES, SNESMSType);
1000 PETSC_EXTERN PetscErrorCode SNESMSGetDamping(SNES, PetscReal *);
1001 PETSC_EXTERN PetscErrorCode SNESMSSetDamping(SNES, PetscReal);
1002 PETSC_EXTERN PetscErrorCode SNESMSFinalizePackage(void);
1003 PETSC_EXTERN PetscErrorCode SNESMSInitializePackage(void);
1004 PETSC_EXTERN PetscErrorCode SNESMSRegisterDestroy(void);
1005 
1006 /*MC
1007    SNESNGMRESRestartType - the restart approach used by `SNESNGMRES`
1008 
1009   Values:
1010 +   `SNES_NGMRES_RESTART_NONE`       - never restart
1011 .   `SNES_NGMRES_RESTART_DIFFERENCE` - restart based upon difference criteria
1012 -   `SNES_NGMRES_RESTART_PERIODIC`   - restart after a fixed number of iterations
1013 
1014   Options Database Keys:
1015 + -snes_ngmres_restart_type <difference,periodic,none> - set the restart type
1016 - -snes_ngmres_restart <30>                            - sets the number of iterations before restart for periodic
1017 
1018    Level: intermediate
1019 
1020 .seealso: `SNES, `SNESNGMRES`, `SNESNGMRESSetSelectType()`, `SNESNGMRESGetSelectType()`, `SNESNGMRESSetRestartType()`,
1021           `SNESNGMRESGetRestartType()`, `SNESNGMRESSelectType`
1022 M*/
1023 typedef enum {
1024   SNES_NGMRES_RESTART_NONE       = 0,
1025   SNES_NGMRES_RESTART_PERIODIC   = 1,
1026   SNES_NGMRES_RESTART_DIFFERENCE = 2
1027 } SNESNGMRESRestartType;
1028 PETSC_EXTERN const char *const SNESNGMRESRestartTypes[];
1029 
1030 /*MC
1031    SNESNGMRESSelectType - the approach used by `SNESNGMRES` to determine how the candidate solution and
1032   combined solution are used to create the next iterate.
1033 
1034    Values:
1035 +   `SNES_NGMRES_SELECT_NONE`       - choose the combined solution all the time
1036 .   `SNES_NGMRES_SELECT_DIFFERENCE` - choose based upon the selection criteria
1037 -   `SNES_NGMRES_SELECT_LINESEARCH` - choose based upon line search combination
1038 
1039   Options Database Key:
1040 . -snes_ngmres_select_type<difference,none,linesearch> - select type
1041 
1042    Level: intermediate
1043 
1044 .seealso: `SNES, `SNESNGMRES`, `SNESNGMRESSetSelectType()`, `SNESNGMRESGetSelectType()`, `SNESNGMRESSetRestartType()`,
1045           `SNESNGMRESGetRestartType()`, `SNESNGMRESRestartType`
1046 M*/
1047 typedef enum {
1048   SNES_NGMRES_SELECT_NONE       = 0,
1049   SNES_NGMRES_SELECT_DIFFERENCE = 1,
1050   SNES_NGMRES_SELECT_LINESEARCH = 2
1051 } SNESNGMRESSelectType;
1052 PETSC_EXTERN const char *const SNESNGMRESSelectTypes[];
1053 
1054 PETSC_EXTERN PetscErrorCode SNESNGMRESSetRestartType(SNES, SNESNGMRESRestartType);
1055 PETSC_EXTERN PetscErrorCode SNESNGMRESSetSelectType(SNES, SNESNGMRESSelectType);
1056 PETSC_EXTERN PetscErrorCode SNESNGMRESSetRestartFmRise(SNES, PetscBool);
1057 PETSC_EXTERN PetscErrorCode SNESNGMRESGetRestartFmRise(SNES, PetscBool *);
1058 
1059 /*MC
1060    SNESNCGType - the conjugate update approach for `SNESNCG`
1061 
1062    Values:
1063 +   `SNES_NCG_FR`  - Fletcher-Reeves update
1064 .   `SNES_NCG_PRP` - Polak-Ribiere-Polyak update, the default and the only one that tolerates generalized search directions
1065 .   `SNES_NCG_HS`  - Hestenes-Steifel update
1066 .   `SNES_NCG_DY`  - Dai-Yuan update
1067 -   `SNES_NCG_CD`  - Conjugate Descent update
1068 
1069   Options Database Key:
1070 . -snes_ncg_type<fr,prp,hs,dy,cd> - select type
1071 
1072    Level: intermediate
1073 
1074 .seealso: `SNES, `SNESNCG`, `SNESNCGSetType()`
1075 M*/
1076 typedef enum {
1077   SNES_NCG_FR  = 0,
1078   SNES_NCG_PRP = 1,
1079   SNES_NCG_HS  = 2,
1080   SNES_NCG_DY  = 3,
1081   SNES_NCG_CD  = 4
1082 } SNESNCGType;
1083 PETSC_EXTERN const char *const SNESNCGTypes[];
1084 
1085 PETSC_EXTERN PetscErrorCode SNESNCGSetType(SNES, SNESNCGType);
1086 
1087 /*MC
1088    SNESQNScaleType - the scaling type used by `SNESQN`
1089 
1090    Values:
1091 +   `SNES_QN_SCALE_NONE`     - don't scale the problem
1092 .   `SNES_QN_SCALE_SCALAR`   - use Shanno scaling
1093 .   `SNES_QN_SCALE_DIAGONAL` - scale with a diagonalized BFGS formula (see Gilbert and Lemarechal 1989), available
1094 -   `SNES_QN_SCALE_JACOBIAN` - scale by solving a linear system coming from the Jacobian you provided with `SNESSetJacobian()`
1095                                computed at the first iteration of `SNESQN` and at ever restart.
1096 
1097     Options Database Key:
1098 . -snes_qn_scale_type <diagonal,none,scalar,jacobian> - Scaling type
1099 
1100    Level: intermediate
1101 
1102 .seealso: `SNES, `SNESQN`, `SNESQNSetScaleType()`, `SNESQNType`, `SNESQNSetType()`, `SNESQNSetRestartType()`, `SNESQNRestartType`
1103 M*/
1104 typedef enum {
1105   SNES_QN_SCALE_DEFAULT  = 0,
1106   SNES_QN_SCALE_NONE     = 1,
1107   SNES_QN_SCALE_SCALAR   = 2,
1108   SNES_QN_SCALE_DIAGONAL = 3,
1109   SNES_QN_SCALE_JACOBIAN = 4
1110 } SNESQNScaleType;
1111 PETSC_EXTERN const char *const SNESQNScaleTypes[];
1112 
1113 /*MC
1114    SNESQNRestartType - the restart approached used by `SNESQN`
1115 
1116    Values:
1117 +   `SNES_QN_RESTART_NONE`     - never restart
1118 .   `SNES_QN_RESTART_POWELL`   - restart based upon descent criteria
1119 -   `SNES_QN_RESTART_PERIODIC` - restart after a fixed number of iterations
1120 
1121   Options Database Keys:
1122 + -snes_qn_restart_type <powell,periodic,none> - set the restart type
1123 - -snes_qn_m <m>                               - sets the number of stored updates and the restart period for periodic
1124 
1125    Level: intermediate
1126 
1127 .seealso: `SNES, `SNESQN`, `SNESQNSetScaleType()`, `SNESQNType`, `SNESQNSetType()`, `SNESQNSetRestartType()`, `SNESQNScaleType`
1128 M*/
1129 typedef enum {
1130   SNES_QN_RESTART_DEFAULT  = 0,
1131   SNES_QN_RESTART_NONE     = 1,
1132   SNES_QN_RESTART_POWELL   = 2,
1133   SNES_QN_RESTART_PERIODIC = 3
1134 } SNESQNRestartType;
1135 PETSC_EXTERN const char *const SNESQNRestartTypes[];
1136 
1137 /*MC
1138    SNESQNType - the type used by `SNESQN`
1139 
1140   Values:
1141 +   `SNES_QN_LBFGS`      - LBFGS variant
1142 .   `SNES_QN_BROYDEN`    - Broyden variant
1143 -   `SNES_QN_BADBROYDEN` - Bad Broyden variant
1144 
1145   Options Database Key:
1146 . -snes_qn_type <lbfgs,broyden,badbroyden> - quasi-Newton type
1147 
1148    Level: intermediate
1149 
1150 .seealso: `SNES, `SNESQN`, `SNESQNSetScaleType()`, `SNESQNSetType()`, `SNESQNScaleType`, `SNESQNRestartType`, `SNESQNSetRestartType()`
1151 M*/
1152 typedef enum {
1153   SNES_QN_LBFGS      = 0,
1154   SNES_QN_BROYDEN    = 1,
1155   SNES_QN_BADBROYDEN = 2
1156 } SNESQNType;
1157 PETSC_EXTERN const char *const SNESQNTypes[];
1158 
1159 PETSC_EXTERN PetscErrorCode SNESQNSetType(SNES, SNESQNType);
1160 PETSC_EXTERN PetscErrorCode SNESQNSetScaleType(SNES, SNESQNScaleType);
1161 PETSC_EXTERN PetscErrorCode SNESQNSetRestartType(SNES, SNESQNRestartType);
1162 
1163 PETSC_EXTERN PetscErrorCode SNESNASMGetType(SNES, PCASMType *);
1164 PETSC_EXTERN PetscErrorCode SNESNASMSetType(SNES, PCASMType);
1165 PETSC_EXTERN PetscErrorCode SNESNASMGetSubdomains(SNES, PetscInt *, SNES **, VecScatter **, VecScatter **, VecScatter **);
1166 PETSC_EXTERN PetscErrorCode SNESNASMSetSubdomains(SNES, PetscInt, SNES *, VecScatter *, VecScatter *, VecScatter *);
1167 PETSC_EXTERN PetscErrorCode SNESNASMSetDamping(SNES, PetscReal);
1168 PETSC_EXTERN PetscErrorCode SNESNASMGetDamping(SNES, PetscReal *);
1169 PETSC_EXTERN PetscErrorCode SNESNASMGetSubdomainVecs(SNES, PetscInt *, Vec **, Vec **, Vec **, Vec **);
1170 PETSC_EXTERN PetscErrorCode SNESNASMSetComputeFinalJacobian(SNES, PetscBool);
1171 PETSC_EXTERN PetscErrorCode SNESNASMGetSNES(SNES, PetscInt, SNES *);
1172 PETSC_EXTERN PetscErrorCode SNESNASMGetNumber(SNES, PetscInt *);
1173 PETSC_EXTERN PetscErrorCode SNESNASMSetWeight(SNES, Vec);
1174 
1175 /*E
1176   SNESCompositeType - Determines how two or more preconditioners are composed with the `SNESType` of `SNESCOMPOSITE`
1177 
1178   Values:
1179 + `SNES_COMPOSITE_ADDITIVE`        - results from application of all preconditioners are added together
1180 . `SNES_COMPOSITE_MULTIPLICATIVE`  - preconditioners are applied sequentially to the residual freshly
1181                                      computed after the previous preconditioner application
1182 - `SNES_COMPOSITE_ADDITIVEOPTIMAL` - uses a linear combination of the solutions obtained with each preconditioner that approximately minimize the function
1183                                      value at the new iteration.
1184 
1185    Level: beginner
1186 
1187 .seealso: [](sec_pc), `PCCOMPOSITE`, `PCFIELDSPLIT`, `PC`, `PCCompositeSetType()`, `PCCompositeType`
1188 E*/
1189 typedef enum {
1190   SNES_COMPOSITE_ADDITIVE,
1191   SNES_COMPOSITE_MULTIPLICATIVE,
1192   SNES_COMPOSITE_ADDITIVEOPTIMAL
1193 } SNESCompositeType;
1194 PETSC_EXTERN const char *const SNESCompositeTypes[];
1195 
1196 PETSC_EXTERN PetscErrorCode SNESCompositeSetType(SNES, SNESCompositeType);
1197 PETSC_EXTERN PetscErrorCode SNESCompositeAddSNES(SNES, SNESType);
1198 PETSC_EXTERN PetscErrorCode SNESCompositeGetSNES(SNES, PetscInt, SNES *);
1199 PETSC_EXTERN PetscErrorCode SNESCompositeGetNumber(SNES, PetscInt *);
1200 PETSC_EXTERN PetscErrorCode SNESCompositeSetDamping(SNES, PetscInt, PetscReal);
1201 
1202 PETSC_EXTERN PetscErrorCode SNESPatchSetDiscretisationInfo(SNES, PetscInt, DM *, PetscInt *, PetscInt *, const PetscInt **, const PetscInt *, PetscInt, const PetscInt *, PetscInt, const PetscInt *);
1203 PETSC_EXTERN PetscErrorCode SNESPatchSetComputeOperator(SNES, PetscErrorCode (*func)(PC, PetscInt, Vec, Mat, IS, PetscInt, const PetscInt *, const PetscInt *, void *), void *);
1204 PETSC_EXTERN PetscErrorCode SNESPatchSetComputeFunction(SNES, PetscErrorCode (*func)(PC, PetscInt, Vec, Vec, IS, PetscInt, const PetscInt *, const PetscInt *, void *), void *);
1205 PETSC_EXTERN PetscErrorCode SNESPatchSetConstructType(SNES, PCPatchConstructType, PetscErrorCode (*func)(PC, PetscInt *, IS **, IS *, void *), void *);
1206 PETSC_EXTERN PetscErrorCode SNESPatchSetCellNumbering(SNES, PetscSection);
1207 
1208 /*E
1209     SNESFASType - Determines the type of nonlinear multigrid method that is run.
1210 
1211    Values:
1212 +  `SNES_FAS_MULTIPLICATIVE` (default) - traditional V or W cycle as determined by `SNESFASSetCycles()`
1213 .  `SNES_FAS_ADDITIVE`                 - additive FAS cycle
1214 .  `SNES_FAS_FULL`                     - full FAS cycle
1215 -  `SNES_FAS_KASKADE`                  - Kaskade FAS cycle
1216 
1217    Level: beginner
1218 
1219 .seealso: [](ch_snes), `SNESFAS`, `PCMGSetType()`, `PCMGType`
1220 E*/
1221 typedef enum {
1222   SNES_FAS_MULTIPLICATIVE,
1223   SNES_FAS_ADDITIVE,
1224   SNES_FAS_FULL,
1225   SNES_FAS_KASKADE
1226 } SNESFASType;
1227 PETSC_EXTERN const char *const SNESFASTypes[];
1228 
1229 /* called on the finest level FAS instance*/
1230 PETSC_EXTERN PetscErrorCode SNESFASSetType(SNES, SNESFASType);
1231 PETSC_EXTERN PetscErrorCode SNESFASGetType(SNES, SNESFASType *);
1232 PETSC_EXTERN PetscErrorCode SNESFASSetLevels(SNES, PetscInt, MPI_Comm *);
1233 PETSC_EXTERN PetscErrorCode SNESFASGetLevels(SNES, PetscInt *);
1234 PETSC_EXTERN PetscErrorCode SNESFASGetCycleSNES(SNES, PetscInt, SNES *);
1235 PETSC_EXTERN PetscErrorCode SNESFASSetNumberSmoothUp(SNES, PetscInt);
1236 PETSC_EXTERN PetscErrorCode SNESFASSetNumberSmoothDown(SNES, PetscInt);
1237 PETSC_EXTERN PetscErrorCode SNESFASSetCycles(SNES, PetscInt);
1238 PETSC_EXTERN PetscErrorCode SNESFASSetMonitor(SNES, PetscViewerAndFormat *, PetscBool);
1239 PETSC_EXTERN PetscErrorCode SNESFASSetLog(SNES, PetscBool);
1240 
1241 PETSC_EXTERN PetscErrorCode SNESFASSetGalerkin(SNES, PetscBool);
1242 PETSC_EXTERN PetscErrorCode SNESFASGetGalerkin(SNES, PetscBool *);
1243 PETSC_EXTERN PetscErrorCode SNESFASGalerkinFunctionDefault(SNES, Vec, Vec, void *);
1244 
1245 /* called on any level -- "Cycle" FAS instance */
1246 PETSC_EXTERN PetscErrorCode SNESFASCycleGetSmoother(SNES, SNES *);
1247 PETSC_EXTERN PetscErrorCode SNESFASCycleGetSmootherUp(SNES, SNES *);
1248 PETSC_EXTERN PetscErrorCode SNESFASCycleGetSmootherDown(SNES, SNES *);
1249 PETSC_EXTERN PetscErrorCode SNESFASCycleGetCorrection(SNES, SNES *);
1250 PETSC_EXTERN PetscErrorCode SNESFASCycleGetInterpolation(SNES, Mat *);
1251 PETSC_EXTERN PetscErrorCode SNESFASCycleGetRestriction(SNES, Mat *);
1252 PETSC_EXTERN PetscErrorCode SNESFASCycleGetInjection(SNES, Mat *);
1253 PETSC_EXTERN PetscErrorCode SNESFASCycleGetRScale(SNES, Vec *);
1254 PETSC_EXTERN PetscErrorCode SNESFASCycleSetCycles(SNES, PetscInt);
1255 PETSC_EXTERN PetscErrorCode SNESFASCycleIsFine(SNES, PetscBool *);
1256 
1257 /* called on the (outer) finest level FAS to set/get parameters on any level instance */
1258 PETSC_EXTERN PetscErrorCode SNESFASSetInterpolation(SNES, PetscInt, Mat);
1259 PETSC_EXTERN PetscErrorCode SNESFASGetInterpolation(SNES, PetscInt, Mat *);
1260 PETSC_EXTERN PetscErrorCode SNESFASSetRestriction(SNES, PetscInt, Mat);
1261 PETSC_EXTERN PetscErrorCode SNESFASGetRestriction(SNES, PetscInt, Mat *);
1262 PETSC_EXTERN PetscErrorCode SNESFASSetInjection(SNES, PetscInt, Mat);
1263 PETSC_EXTERN PetscErrorCode SNESFASGetInjection(SNES, PetscInt, Mat *);
1264 PETSC_EXTERN PetscErrorCode SNESFASSetRScale(SNES, PetscInt, Vec);
1265 PETSC_EXTERN PetscErrorCode SNESFASGetRScale(SNES, PetscInt, Vec *);
1266 PETSC_EXTERN PetscErrorCode SNESFASSetContinuation(SNES, PetscBool);
1267 
1268 PETSC_EXTERN PetscErrorCode SNESFASGetSmoother(SNES, PetscInt, SNES *);
1269 PETSC_EXTERN PetscErrorCode SNESFASGetSmootherUp(SNES, PetscInt, SNES *);
1270 PETSC_EXTERN PetscErrorCode SNESFASGetSmootherDown(SNES, PetscInt, SNES *);
1271 PETSC_EXTERN PetscErrorCode SNESFASGetCoarseSolve(SNES, SNES *);
1272 
1273 /* parameters for full FAS */
1274 PETSC_EXTERN PetscErrorCode SNESFASFullSetDownSweep(SNES, PetscBool);
1275 PETSC_EXTERN PetscErrorCode SNESFASCreateCoarseVec(SNES, Vec *);
1276 PETSC_EXTERN PetscErrorCode SNESFASRestrict(SNES, Vec, Vec);
1277 PETSC_EXTERN PetscErrorCode SNESFASFullSetTotal(SNES, PetscBool);
1278 PETSC_EXTERN PetscErrorCode SNESFASFullGetTotal(SNES, PetscBool *);
1279 
1280 PETSC_EXTERN PetscErrorCode DMSNESCheckDiscretization(SNES, DM, PetscReal, Vec, PetscReal, PetscReal[]);
1281 PETSC_EXTERN PetscErrorCode DMSNESCheckResidual(SNES, DM, Vec, PetscReal, PetscReal *);
1282 PETSC_EXTERN PetscErrorCode DMSNESCheckJacobian(SNES, DM, Vec, PetscReal, PetscBool *, PetscReal *);
1283 PETSC_EXTERN PetscErrorCode DMSNESCheckFromOptions(SNES, Vec);
1284 PETSC_EXTERN PetscErrorCode DMSNESComputeJacobianAction(DM, Vec, Vec, Vec, void *);
1285 PETSC_EXTERN PetscErrorCode DMSNESCreateJacobianMF(DM, Vec, void *, Mat *);
1286