Actual source code: petscsnes.h

  1: /*
  2:     User interface for the nonlinear solvers package.
  3: */
  4: #pragma once

  6: #include <petscksp.h>
  7: #include <petscdmtypes.h>
  8: #include <petscfvtypes.h>
  9: #include <petscdmdatypes.h>
 10: #include <petscsnestypes.h>

 12: /* SUBMANSEC = SNES */

 14: /*J
 15:    SNESType - String with the name of a PETSc `SNES` method.

 17:    Level: beginner

 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: #define SNESNEWTONAL         "newtonal"

 45: /* Logging support */
 46: PETSC_EXTERN PetscClassId SNES_CLASSID;
 47: PETSC_EXTERN PetscClassId DMSNES_CLASSID;

 49: PETSC_EXTERN PetscErrorCode SNESInitializePackage(void);
 50: PETSC_EXTERN PetscErrorCode SNESFinalizePackage(void);

 52: PETSC_EXTERN PetscErrorCode SNESCreate(MPI_Comm, SNES *);
 53: PETSC_EXTERN PetscErrorCode SNESParametersInitialize(SNES);
 54: PETSC_EXTERN PetscErrorCode SNESReset(SNES);
 55: PETSC_EXTERN PetscErrorCode SNESDestroy(SNES *);
 56: PETSC_EXTERN PetscErrorCode SNESSetType(SNES, SNESType);
 57: PETSC_EXTERN PetscErrorCode SNESMonitor(SNES, PetscInt, PetscReal);
 58: PETSC_EXTERN PetscErrorCode SNESMonitorSet(SNES, PetscErrorCode (*)(SNES, PetscInt, PetscReal, void *), void *, PetscCtxDestroyFn *);
 59: PETSC_EXTERN PetscErrorCode SNESMonitorSetFromOptions(SNES, const char[], const char[], const char[], PetscErrorCode (*)(SNES, PetscInt, PetscReal, PetscViewerAndFormat *), PetscErrorCode (*)(SNES, PetscViewerAndFormat *));
 60: PETSC_EXTERN PetscErrorCode SNESMonitorCancel(SNES);
 61: PETSC_EXTERN PetscErrorCode SNESMonitorSAWs(SNES, PetscInt, PetscReal, void *);
 62: PETSC_EXTERN PetscErrorCode SNESMonitorSAWsCreate(SNES, void **);
 63: PETSC_EXTERN PetscErrorCode SNESMonitorSAWsDestroy(void **);
 64: PETSC_EXTERN PetscErrorCode SNESSetConvergenceHistory(SNES, PetscReal[], PetscInt[], PetscInt, PetscBool);
 65: PETSC_EXTERN PetscErrorCode SNESGetConvergenceHistory(SNES, PetscReal *[], PetscInt *[], PetscInt *);
 66: PETSC_EXTERN PetscErrorCode SNESSetUp(SNES);
 67: PETSC_EXTERN PetscErrorCode SNESSolve(SNES, Vec, Vec);
 68: PETSC_EXTERN PetscErrorCode SNESSetErrorIfNotConverged(SNES, PetscBool);
 69: PETSC_EXTERN PetscErrorCode SNESGetErrorIfNotConverged(SNES, PetscBool *);
 70: PETSC_EXTERN PetscErrorCode SNESConverged(SNES, PetscInt, PetscReal, PetscReal, PetscReal);

 72: PETSC_EXTERN PetscErrorCode SNESSetWorkVecs(SNES, PetscInt);

 74: PETSC_EXTERN PetscErrorCode SNESAddOptionsChecker(PetscErrorCode (*)(SNES));

 76: PETSC_EXTERN PetscErrorCode SNESRegister(const char[], PetscErrorCode (*)(SNES));

 78: PETSC_EXTERN PetscErrorCode SNESGetKSP(SNES, KSP *);
 79: PETSC_EXTERN PetscErrorCode SNESSetKSP(SNES, KSP);
 80: PETSC_EXTERN PetscErrorCode SNESSetSolution(SNES, Vec);
 81: PETSC_EXTERN PetscErrorCode SNESGetSolution(SNES, Vec *);
 82: PETSC_EXTERN PetscErrorCode SNESGetSolutionUpdate(SNES, Vec *);
 83: PETSC_EXTERN PetscErrorCode SNESGetRhs(SNES, Vec *);
 84: PETSC_EXTERN PetscErrorCode SNESView(SNES, PetscViewer);
 85: PETSC_EXTERN PetscErrorCode SNESLoad(SNES, PetscViewer);
 86: PETSC_EXTERN PetscErrorCode SNESConvergedReasonViewSet(SNES, PetscErrorCode (*)(SNES, void *), void *, PetscCtxDestroyFn *);
 87: PETSC_EXTERN PetscErrorCode SNESViewFromOptions(SNES, PetscObject, const char[]);
 88: PETSC_EXTERN PetscErrorCode SNESConvergedReasonView(SNES, PetscViewer);
 89: PETSC_EXTERN PetscErrorCode SNESConvergedReasonViewFromOptions(SNES);
 90: PETSC_EXTERN PetscErrorCode SNESConvergedReasonViewCancel(SNES);

 92: PETSC_DEPRECATED_FUNCTION(3, 14, 0, "SNESConvergedReasonView()", ) static inline PetscErrorCode SNESReasonView(SNES snes, PetscViewer v)
 93: {
 94:   return SNESConvergedReasonView(snes, v);
 95: }
 96: PETSC_DEPRECATED_FUNCTION(3, 14, 0, "SNESConvergedReasonViewFromOptions()", ) static inline PetscErrorCode SNESReasonViewFromOptions(SNES snes)
 97: {
 98:   return SNESConvergedReasonViewFromOptions(snes);
 99: }

101: #define SNES_FILE_CLASSID 1211224

103: PETSC_EXTERN PetscErrorCode SNESSetOptionsPrefix(SNES, const char[]);
104: PETSC_EXTERN PetscErrorCode SNESAppendOptionsPrefix(SNES, const char[]);
105: PETSC_EXTERN PetscErrorCode SNESGetOptionsPrefix(SNES, const char *[]);
106: PETSC_EXTERN PetscErrorCode SNESSetFromOptions(SNES);
107: PETSC_EXTERN PetscErrorCode SNESResetFromOptions(SNES);

109: PETSC_EXTERN PetscErrorCode SNESSetUseMatrixFree(SNES, PetscBool, PetscBool);
110: PETSC_EXTERN PetscErrorCode SNESGetUseMatrixFree(SNES, PetscBool *, PetscBool *);
111: PETSC_EXTERN PetscErrorCode MatCreateSNESMF(SNES, Mat *);
112: PETSC_EXTERN PetscErrorCode MatSNESMFGetSNES(Mat, SNES *);
113: PETSC_EXTERN PetscErrorCode MatSNESMFSetReuseBase(Mat, PetscBool);
114: PETSC_EXTERN PetscErrorCode MatSNESMFGetReuseBase(Mat, PetscBool *);
115: PETSC_EXTERN PetscErrorCode MatMFFDComputeJacobian(SNES, Vec, Mat, Mat, void *);
116: PETSC_EXTERN PetscErrorCode MatCreateSNESMFMore(SNES, Vec, Mat *);
117: PETSC_EXTERN PetscErrorCode MatSNESMFMoreSetParameters(Mat, PetscReal, PetscReal, PetscReal);

119: PETSC_EXTERN PetscErrorCode SNESGetType(SNES, SNESType *);
120: PETSC_EXTERN PetscErrorCode SNESMonitorDefaultSetUp(SNES, PetscViewerAndFormat *);
121: PETSC_EXTERN PetscErrorCode SNESMonitorDefault(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
122: PETSC_EXTERN PetscErrorCode SNESMonitorScaling(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
123: PETSC_EXTERN PetscErrorCode SNESMonitorRange(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
124: PETSC_EXTERN PetscErrorCode SNESMonitorRatio(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
125: PETSC_EXTERN PetscErrorCode SNESMonitorRatioSetUp(SNES, PetscViewerAndFormat *);
126: PETSC_EXTERN PetscErrorCode SNESMonitorSolution(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
127: PETSC_EXTERN PetscErrorCode SNESMonitorResidual(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
128: PETSC_EXTERN PetscErrorCode SNESMonitorSolutionUpdate(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
129: PETSC_EXTERN PetscErrorCode SNESMonitorDefaultShort(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
130: PETSC_EXTERN PetscErrorCode SNESMonitorDefaultField(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
131: PETSC_EXTERN PetscErrorCode SNESMonitorJacUpdateSpectrum(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
132: PETSC_EXTERN PetscErrorCode SNESMonitorFields(SNES, PetscInt, PetscReal, PetscViewerAndFormat *);
133: PETSC_EXTERN PetscErrorCode KSPMonitorSNESResidual(KSP, PetscInt, PetscReal, PetscViewerAndFormat *);
134: PETSC_EXTERN PetscErrorCode KSPMonitorSNESResidualDrawLG(KSP, PetscInt, PetscReal, PetscViewerAndFormat *);
135: PETSC_EXTERN PetscErrorCode KSPMonitorSNESResidualDrawLGCreate(PetscViewer, PetscViewerFormat, void *, PetscViewerAndFormat **);

137: PETSC_EXTERN PetscErrorCode SNESSetTolerances(SNES, PetscReal, PetscReal, PetscReal, PetscInt, PetscInt);
138: PETSC_EXTERN PetscErrorCode SNESSetDivergenceTolerance(SNES, PetscReal);
139: PETSC_EXTERN PetscErrorCode SNESGetTolerances(SNES, PetscReal *, PetscReal *, PetscReal *, PetscInt *, PetscInt *);
140: PETSC_EXTERN PetscErrorCode SNESGetDivergenceTolerance(SNES, PetscReal *);
141: PETSC_EXTERN PetscErrorCode SNESGetForceIteration(SNES, PetscBool *);
142: PETSC_EXTERN PetscErrorCode SNESSetForceIteration(SNES, PetscBool);
143: PETSC_EXTERN PetscErrorCode SNESGetIterationNumber(SNES, PetscInt *);
144: PETSC_EXTERN PetscErrorCode SNESSetIterationNumber(SNES, PetscInt);

146: /*E
147:    SNESNewtonTRFallbackType - type of fallback in case the solution of the trust-region subproblem is outside of the radius

149:    Values:
150: +  `SNES_TR_FALLBACK_NEWTON` - use scaled Newton step
151: .  `SNES_TR_FALLBACK_CAUCHY` - use Cauchy direction
152: -  `SNES_TR_FALLBACK_DOGLEG` - use dogleg method

154:    Level: intermediate

156: .seealso: [](ch_snes), `SNES`, `SNESNEWTONTR`, `SNESNEWTONTRDC`
157: E*/
158: typedef enum {
159:   SNES_TR_FALLBACK_NEWTON,
160:   SNES_TR_FALLBACK_CAUCHY,
161:   SNES_TR_FALLBACK_DOGLEG,
162: } SNESNewtonTRFallbackType;

164: PETSC_EXTERN const char *const SNESNewtonTRFallbackTypes[];

166: PETSC_EXTERN PetscErrorCode SNESNewtonTRSetPreCheck(SNES, PetscErrorCode (*)(SNES, Vec, Vec, PetscBool *, void *), void *ctx);
167: PETSC_EXTERN PetscErrorCode SNESNewtonTRGetPreCheck(SNES, PetscErrorCode (**)(SNES, Vec, Vec, PetscBool *, void *), void **ctx);
168: PETSC_EXTERN PetscErrorCode SNESNewtonTRSetPostCheck(SNES, PetscErrorCode (*)(SNES, Vec, Vec, Vec, PetscBool *, PetscBool *, void *), void *ctx);
169: PETSC_EXTERN PetscErrorCode SNESNewtonTRGetPostCheck(SNES, PetscErrorCode (**)(SNES, Vec, Vec, Vec, PetscBool *, PetscBool *, void *), void **ctx);
170: PETSC_EXTERN PetscErrorCode SNESNewtonTRSetFallbackType(SNES, SNESNewtonTRFallbackType);
171: PETSC_EXTERN PetscErrorCode SNESNewtonTRPreCheck(SNES, Vec, Vec, PetscBool *);
172: PETSC_EXTERN PetscErrorCode SNESNewtonTRPostCheck(SNES, Vec, Vec, Vec, PetscBool *, PetscBool *);
173: PETSC_EXTERN PetscErrorCode SNESNewtonTRSetNormType(SNES, NormType);

175: /*E
176:     SNESNewtonTRQNType - type of quasi-Newton model to use

178:    Values:
179: +  `SNES_TR_QN_NONE` - do not use a quasi-Newton model
180: .  `SNES_TR_QN_SAME` - use the same quasi-Newton model for matrix and preconditioner
181: -  `SNES_TR_QN_DIFFERENT` - use different quasi-Newton models for matrix and preconditioner

183:    Level: intermediate

185: .seealso: [](ch_snes), `SNES`, `SNESNEWTONTR`
186: E*/
187: typedef enum {
188:   SNES_TR_QN_NONE,
189:   SNES_TR_QN_SAME,
190:   SNES_TR_QN_DIFFERENT,
191: } SNESNewtonTRQNType;

193: PETSC_EXTERN const char *const SNESNewtonTRQNTypes[];

195: PETSC_EXTERN PetscErrorCode SNESNewtonTRSetQNType(SNES, SNESNewtonTRQNType);

197: PETSC_EXTERN PETSC_DEPRECATED_FUNCTION(3, 22, 0, "SNESNewtonTRSetTolerances()", ) PetscErrorCode SNESSetTrustRegionTolerance(SNES, PetscReal);
198: PETSC_EXTERN PetscErrorCode SNESNewtonTRSetTolerances(SNES, PetscReal, PetscReal, PetscReal);
199: PETSC_EXTERN PetscErrorCode SNESNewtonTRGetTolerances(SNES, PetscReal *, PetscReal *, PetscReal *);
200: PETSC_EXTERN PetscErrorCode SNESNewtonTRSetUpdateParameters(SNES, PetscReal, PetscReal, PetscReal, PetscReal, PetscReal);
201: PETSC_EXTERN PetscErrorCode SNESNewtonTRGetUpdateParameters(SNES, PetscReal *, PetscReal *, PetscReal *, PetscReal *, PetscReal *);

203: PETSC_EXTERN PetscErrorCode SNESNewtonTRDCGetRhoFlag(SNES, PetscBool *);
204: PETSC_EXTERN PetscErrorCode SNESNewtonTRDCSetPreCheck(SNES, PetscErrorCode (*)(SNES, Vec, Vec, PetscBool *, void *), void *ctx);
205: PETSC_EXTERN PetscErrorCode SNESNewtonTRDCGetPreCheck(SNES, PetscErrorCode (**)(SNES, Vec, Vec, PetscBool *, void *), void **ctx);
206: PETSC_EXTERN PetscErrorCode SNESNewtonTRDCSetPostCheck(SNES, PetscErrorCode (*)(SNES, Vec, Vec, Vec, PetscBool *, PetscBool *, void *), void *ctx);
207: PETSC_EXTERN PetscErrorCode SNESNewtonTRDCGetPostCheck(SNES, PetscErrorCode (**)(SNES, Vec, Vec, Vec, PetscBool *, PetscBool *, void *), void **ctx);

209: PETSC_EXTERN PetscErrorCode SNESGetNonlinearStepFailures(SNES, PetscInt *);
210: PETSC_EXTERN PetscErrorCode SNESSetMaxNonlinearStepFailures(SNES, PetscInt);
211: PETSC_EXTERN PetscErrorCode SNESGetMaxNonlinearStepFailures(SNES, PetscInt *);
212: PETSC_EXTERN PetscErrorCode SNESGetNumberFunctionEvals(SNES, PetscInt *);

214: PETSC_EXTERN PetscErrorCode SNESSetLagPreconditioner(SNES, PetscInt);
215: PETSC_EXTERN PetscErrorCode SNESGetLagPreconditioner(SNES, PetscInt *);
216: PETSC_EXTERN PetscErrorCode SNESSetLagJacobian(SNES, PetscInt);
217: PETSC_EXTERN PetscErrorCode SNESGetLagJacobian(SNES, PetscInt *);
218: PETSC_EXTERN PetscErrorCode SNESSetLagPreconditionerPersists(SNES, PetscBool);
219: PETSC_EXTERN PetscErrorCode SNESSetLagJacobianPersists(SNES, PetscBool);
220: PETSC_EXTERN PetscErrorCode SNESSetGridSequence(SNES, PetscInt);
221: PETSC_EXTERN PetscErrorCode SNESGetGridSequence(SNES, PetscInt *);

223: PETSC_EXTERN PetscErrorCode SNESGetLinearSolveIterations(SNES, PetscInt *);
224: PETSC_EXTERN PetscErrorCode SNESGetLinearSolveFailures(SNES, PetscInt *);
225: PETSC_EXTERN PetscErrorCode SNESSetMaxLinearSolveFailures(SNES, PetscInt);
226: PETSC_EXTERN PetscErrorCode SNESGetMaxLinearSolveFailures(SNES, PetscInt *);
227: PETSC_EXTERN PetscErrorCode SNESSetCountersReset(SNES, PetscBool);
228: PETSC_EXTERN PetscErrorCode SNESResetCounters(SNES);

230: PETSC_EXTERN PetscErrorCode SNESKSPSetUseEW(SNES, PetscBool);
231: PETSC_EXTERN PetscErrorCode SNESKSPGetUseEW(SNES, PetscBool *);
232: PETSC_EXTERN PetscErrorCode SNESKSPSetParametersEW(SNES, PetscInt, PetscReal, PetscReal, PetscReal, PetscReal, PetscReal, PetscReal);
233: PETSC_EXTERN PetscErrorCode SNESKSPGetParametersEW(SNES, PetscInt *, PetscReal *, PetscReal *, PetscReal *, PetscReal *, PetscReal *, PetscReal *);

235: #include <petscdrawtypes.h>
236: PETSC_EXTERN PetscErrorCode SNESMonitorLGRange(SNES, PetscInt, PetscReal, void *);

238: PETSC_EXTERN PetscErrorCode SNESSetApplicationContext(SNES, void *);
239: PETSC_EXTERN PetscErrorCode SNESGetApplicationContext(SNES, void *);
240: PETSC_EXTERN PetscErrorCode SNESSetComputeApplicationContext(SNES, PetscErrorCode (*)(SNES, void **), PetscCtxDestroyFn *);

242: PETSC_EXTERN PetscErrorCode SNESPythonSetType(SNES, const char[]);
243: PETSC_EXTERN PetscErrorCode SNESPythonGetType(SNES, const char *[]);

245: PETSC_EXTERN PetscErrorCode SNESSetFunctionDomainError(SNES);
246: PETSC_EXTERN PetscErrorCode SNESGetFunctionDomainError(SNES, PetscBool *);
247: PETSC_EXTERN PetscErrorCode SNESGetJacobianDomainError(SNES, PetscBool *);
248: PETSC_EXTERN PetscErrorCode SNESSetJacobianDomainError(SNES);
249: PETSC_EXTERN PetscErrorCode SNESSetCheckJacobianDomainError(SNES, PetscBool);
250: PETSC_EXTERN PetscErrorCode SNESGetCheckJacobianDomainError(SNES, PetscBool *);

252: #define SNES_CONVERGED_TR_DELTA_DEPRECATED SNES_CONVERGED_TR_DELTA PETSC_DEPRECATED_ENUM(3, 12, 0, "SNES_DIVERGED_TR_DELTA", )
253: /*E
254:     SNESConvergedReason - reason a `SNESSolve()` was determined to have converged or diverged

256:    Values:
257: +  `SNES_CONVERGED_FNORM_ABS`      - 2-norm(F) <= abstol
258: .  `SNES_CONVERGED_FNORM_RELATIVE` - 2-norm(F) <= rtol*2-norm(F(x_0)) where x_0 is the initial guess
259: .  `SNES_CONVERGED_SNORM_RELATIVE` - The 2-norm of the last step <= stol * 2-norm(x) where x is the current
260: .  `SNES_CONVERGED_USER`           - The user has indicated convergence for an arbitrary reason
261: .  `SNES_DIVERGED_FUNCTION_COUNT`  - The user provided function has been called more times than the maximum set in `SNESSetTolerances()`
262: .  `SNES_DIVERGED_DTOL`            - The norm of the function has increased by a factor of divtol set with `SNESSetDivergenceTolerance()`
263: .  `SNES_DIVERGED_FNORM_NAN`       - the 2-norm of the current function evaluation is not-a-number (NaN), this
264:                                      is usually caused by a division of 0 by 0.
265: .  `SNES_DIVERGED_MAX_IT`          - `SNESSolve()` has reached the maximum number of iterations requested
266: .  `SNES_DIVERGED_LINE_SEARCH`     - The line search has failed. This only occurs for `SNES` solvers that use a line search
267: .  `SNES_DIVERGED_LOCAL_MIN`       - the algorithm seems to have stagnated at a local minimum that is not zero.
268: .  `SNES_DIVERGED_USER`            - The user has indicated divergence for an arbitrary reason
269: -  `SNES_CONVERGED_ITERATING       - this only occurs if `SNESGetConvergedReason()` is called during the `SNESSolve()`

271:    Level: beginner

273:     Notes:
274:    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
275:    testing with `-pc_type lu` to eliminate the linear solver as the cause of the problem).

277:    `SNES_DIVERGED_LOCAL_MIN` can only occur when using the line-search variant of `SNES`.
278:    The line search wants to minimize Q(alpha) = 1/2 || F(x + alpha s) ||^2_2  this occurs
279:    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
280:    you get Q'(alpha) = -F(x)^T F'(x)^(-1)^T F'(x+alpha s)F(x+alpha s); when alpha = 0
281:    Q'(0) = - ||F(x)||^2_2 which is always NEGATIVE if F'(x) is invertible. This means the Newton
282:    direction is a descent direction and the line search should succeed if alpha is small enough.

284:    If F'(x) is NOT invertible AND F'(x)^T F(x) = 0 then Q'(0) = 0 and the Newton direction
285:    is NOT a descent direction so the line search will fail. All one can do at this point
286:    is change the initial guess and try again.

288:    An alternative explanation: Newton's method can be regarded as replacing the function with
289:    its linear approximation and minimizing the 2-norm of that. That is F(x+s) approx F(x) + F'(x)s
290:    so we minimize || F(x) + F'(x) s ||^2_2; do this using Least Squares. If F'(x) is invertible then
291:    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
292:    exists a nontrivial (that is F'(x)s != 0) solution to the equation and this direction is
293:    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)
294:    = - (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
295:    and F'(x)^T F'(x) has no negative eigenvalues Q'(0) < 0 so s is a descent direction and the line
296:    search should succeed for small enough alpha.

298:    Note that this RARELY happens in practice. Far more likely the linear system is not being solved
299:    (well enough?) or the Jacobian is wrong.

301:    `SNES_DIVERGED_MAX_IT` means that the solver reached the maximum number of iterations without satisfying any
302:    convergence criteria. `SNES_CONVERGED_ITS` means that `SNESConvergedSkip()` was chosen as the convergence test;
303:    thus the usual convergence criteria have not been checked and may or may not be satisfied.

305: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `KSPConvergedReason`, `SNESSetConvergenceTest()`, `SNESSetTolerances()`
306: E*/
307: typedef enum {                       /* converged */
308:   SNES_CONVERGED_FNORM_ABS      = 2, /* ||F|| < atol */
309:   SNES_CONVERGED_FNORM_RELATIVE = 3, /* ||F|| < rtol*||F_initial|| */
310:   SNES_CONVERGED_SNORM_RELATIVE = 4, /* Newton computed step size small; || delta x || < stol || x ||*/
311:   SNES_CONVERGED_ITS            = 5, /* maximum iterations reached */
312:   SNES_BREAKOUT_INNER_ITER      = 6, /* Flag to break out of inner loop after checking custom convergence.
313:                                         It is used in multi-phase flow when state changes */
314:   SNES_CONVERGED_USER           = 7, /* The user has indicated convergence for an arbitrary reason */
315:   /* diverged */
316:   SNES_DIVERGED_FUNCTION_DOMAIN      = -1, /* the new x location passed the function is not in the domain of F */
317:   SNES_DIVERGED_FUNCTION_COUNT       = -2,
318:   SNES_DIVERGED_LINEAR_SOLVE         = -3, /* the linear solve failed */
319:   SNES_DIVERGED_FNORM_NAN            = -4,
320:   SNES_DIVERGED_MAX_IT               = -5,
321:   SNES_DIVERGED_LINE_SEARCH          = -6,  /* the line search failed */
322:   SNES_DIVERGED_INNER                = -7,  /* inner solve failed */
323:   SNES_DIVERGED_LOCAL_MIN            = -8,  /* || J^T b || is small, implies converged to local minimum of F() */
324:   SNES_DIVERGED_DTOL                 = -9,  /* || F || > divtol*||F_initial|| */
325:   SNES_DIVERGED_JACOBIAN_DOMAIN      = -10, /* Jacobian calculation does not make sense */
326:   SNES_DIVERGED_TR_DELTA             = -11,
327:   SNES_CONVERGED_TR_DELTA_DEPRECATED = -11,
328:   SNES_DIVERGED_USER                 = -12, /* The user has indicated divergence for an arbitrary reason */

330:   SNES_CONVERGED_ITERATING = 0
331: } SNESConvergedReason;
332: PETSC_EXTERN const char *const *SNESConvergedReasons;

334: /*MC
335:    SNES_CONVERGED_FNORM_ABS - 2-norm(F) <= abstol

337:    Level: beginner

339: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`
340: M*/

342: /*MC
343:    SNES_CONVERGED_FNORM_RELATIVE - 2-norm(F) <= rtol*2-norm(F(x_0)) where x_0 is the initial guess

345:    Level: beginner

347: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`
348: M*/

350: /*MC
351:   SNES_CONVERGED_SNORM_RELATIVE - The 2-norm of the last step <= stol * 2-norm(x) where x is the current
352:   solution and stol is the 4th argument to `SNESSetTolerances()`

354:   Options Database Key:
355:   -snes_stol <stol> - the step tolerance

357:    Level: beginner

359: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`
360: M*/

362: /*MC
363:    SNES_DIVERGED_FUNCTION_COUNT - The user provided function has been called more times then the final
364:    argument to `SNESSetTolerances()`

366:    Level: beginner

368: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`
369: M*/

371: /*MC
372:    SNES_DIVERGED_DTOL - The norm of the function has increased by a factor of divtol set with `SNESSetDivergenceTolerance()`

374:    Level: beginner

376: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`, `SNESSetDivergenceTolerance()`
377: M*/

379: /*MC
380:    SNES_DIVERGED_FNORM_NAN - the 2-norm of the current function evaluation is not-a-number (NaN), this
381:    is usually caused by a division of 0 by 0.

383:    Level: beginner

385: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`
386: M*/

388: /*MC
389:    SNES_DIVERGED_MAX_IT - SNESSolve() has reached the maximum number of iterations requested

391:    Level: beginner

393: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`
394: M*/

396: /*MC
397:    SNES_DIVERGED_LINE_SEARCH - The line search has failed. This only occurs for a `SNES` solvers that use a line search

399:    Level: beginner

401: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`, `SNESLineSearch`
402: M*/

404: /*MC
405:    SNES_DIVERGED_LOCAL_MIN - the algorithm seems to have stagnated at a local minimum that is not zero.
406:    See the manual page for `SNESConvergedReason` for more details

408:    Level: beginner

410: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`
411: M*/

413: /*MC
414:    SNES_CONERGED_ITERATING - this only occurs if `SNESGetConvergedReason()` is called during the `SNESSolve()`

416:    Level: beginner

418: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `SNESConvergedReason`, `SNESSetTolerances()`
419: M*/

421: PETSC_EXTERN PetscErrorCode SNESSetConvergenceTest(SNES, PetscErrorCode (*)(SNES, PetscInt, PetscReal, PetscReal, PetscReal, SNESConvergedReason *, void *), void *, PetscErrorCode (*)(void *));
422: PETSC_EXTERN PetscErrorCode SNESConvergedDefault(SNES, PetscInt, PetscReal, PetscReal, PetscReal, SNESConvergedReason *, void *);
423: PETSC_EXTERN PetscErrorCode SNESConvergedSkip(SNES, PetscInt, PetscReal, PetscReal, PetscReal, SNESConvergedReason *, void *);
424: PETSC_EXTERN PetscErrorCode SNESConvergedCorrectPressure(SNES, PetscInt, PetscReal, PetscReal, PetscReal, SNESConvergedReason *, void *);
425: PETSC_EXTERN PetscErrorCode SNESGetConvergedReason(SNES, SNESConvergedReason *);
426: PETSC_EXTERN PetscErrorCode SNESGetConvergedReasonString(SNES, const char **);
427: PETSC_EXTERN PetscErrorCode SNESSetConvergedReason(SNES, SNESConvergedReason);

429: PETSC_DEPRECATED_FUNCTION(3, 5, 0, "SNESConvergedSkip()", ) static inline void SNESSkipConverged(void)
430: { /* never called */
431: }
432: #define SNESSkipConverged (SNESSkipConverged, SNESConvergedSkip)

434: /*S
435:   SNESInitialGuessFn - A prototype of a `SNES` compute initial guess function that would be passed to `SNESSetComputeInitialGuess()`

437:   Calling Sequence:
438: + snes  - `SNES` context
439: . u   - output vector to contain initial guess
440: - ctx - [optional] user-defined function context

442:   Level: beginner

444: .seealso: [](ch_snes), `SNES`, `SNESSetComputeInitialGuess()`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESJacobianFn`, `SNESFunctionFn`
445: S*/
446: PETSC_EXTERN_TYPEDEF typedef PetscErrorCode(SNESInitialGuessFn)(SNES snes, Vec u, void *ctx);

448: /*S
449:   SNESFunctionFn - A prototype of a `SNES` evaluation function that would be passed to `SNESSetFunction()`

451:   Calling Sequence:
452: + snes  - `SNES` context
453: . u   - input vector
454: . F   - function vector
455: - ctx - [optional] user-defined function context

457:   Level: beginner

459: .seealso: [](ch_snes), `SNES`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESJacobianFn`, `SNESNGSFn`
460: S*/
461: PETSC_EXTERN_TYPEDEF typedef PetscErrorCode(SNESFunctionFn)(SNES snes, Vec u, Vec F, void *ctx);

463: /*S
464:   SNESObjectiveFn - A prototype of a `SNES` objective evaluation function that would be passed to `SNESSetObjective()`

466:   Calling Sequence:
467: + snes  - `SNES` context
468: . u   - input vector
469: . o   - output value
470: - ctx - [optional] user-defined function context

472:   Level: beginner

474: .seealso: [](ch_snes), `SNES`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESJacobianFn`, `SNESNGSFn`
475: S*/
476: PETSC_EXTERN_TYPEDEF typedef PetscErrorCode(SNESObjectiveFn)(SNES snes, Vec u, PetscReal *o, void *ctx);

478: /*S
479:   SNESJacobianFn - A prototype of a `SNES` Jacobian evaluation function that would be passed to `SNESSetJacobian()`

481:   Calling Sequence:
482: + snes   - the `SNES` context obtained from `SNESCreate()`
483: . u    - input vector
484: . Amat - (approximate) Jacobian matrix
485: . Pmat - matrix used to construct the preconditioner, often the same as `Amat`
486: - ctx  - [optional] user-defined context for matrix evaluation routine

488:   Level: beginner

490: .seealso: [](ch_snes), `SNES`, `SNESSetJacobian()`, `SNESGetJacobian()`, `SNESFunctionFn`, `SNESNGSFn`
491: S*/
492: PETSC_EXTERN_TYPEDEF typedef PetscErrorCode(SNESJacobianFn)(SNES snes, Vec u, Mat Amat, Mat Pmat, void *ctx);

494: /*S
495:   SNESNGSFn - A prototype of a `SNES` nonlinear Gauss-Seidel function that would be passed to `SNESSetNGS()`

497:   Calling Sequence:
498: + snes   - the `SNES` context obtained from `SNESCreate()`
499: . u    - the current solution, updated in place
500: . b    - the right-hand side vector (which may be `NULL`)
501: - ctx  - [optional] user-defined context for matrix evaluation routine

503:   Level: beginner

505: .seealso: [](ch_snes), `SNES`, `SNESSetJacobian()`, `SNESGetJacobian()`, `SNESFunctionFn`, `SNESSetFunction()`, `SNESGetFunction()`, `SNESJacobianFn`
506: S*/
507: PETSC_EXTERN_TYPEDEF typedef PetscErrorCode(SNESNGSFn)(SNES snes, Vec u, Vec b, void *ctx);

509: /*S
510:   SNESUpdateFn - A prototype of a `SNES` update function that would be passed to `SNESSetUpdate()`

512:   Calling Sequence:
513: + snes - `SNES` context
514: - step - the current iteration index

516:   Level: advanced

518: .seealso: [](ch_snes), `SNES`, `SNESSetUpdate()`
519: S*/
520: PETSC_EXTERN_TYPEDEF typedef PetscErrorCode(SNESUpdateFn)(SNES snes, PetscInt step);

522: /* --------- Solving systems of nonlinear equations --------------- */
523: PETSC_EXTERN PetscErrorCode SNESSetFunction(SNES, Vec, SNESFunctionFn *, void *);
524: PETSC_EXTERN PetscErrorCode SNESGetFunction(SNES, Vec *, SNESFunctionFn **, void **);
525: PETSC_EXTERN PetscErrorCode SNESComputeFunction(SNES, Vec, Vec);
526: PETSC_EXTERN PetscErrorCode SNESComputeMFFunction(SNES, Vec, Vec);
527: PETSC_EXTERN PetscErrorCode SNESSetInitialFunction(SNES, Vec);

529: PETSC_EXTERN PetscErrorCode SNESSetJacobian(SNES, Mat, Mat, SNESJacobianFn *, void *);
530: PETSC_EXTERN PetscErrorCode SNESGetJacobian(SNES, Mat *, Mat *, SNESJacobianFn **, void **);
531: PETSC_EXTERN SNESFunctionFn SNESObjectiveComputeFunctionDefaultFD;
532: PETSC_EXTERN SNESJacobianFn SNESComputeJacobianDefault;
533: PETSC_EXTERN SNESJacobianFn SNESComputeJacobianDefaultColor;
534: PETSC_EXTERN PetscErrorCode SNESPruneJacobianColor(SNES, Mat, Mat);
535: PETSC_EXTERN PetscErrorCode SNESSetComputeInitialGuess(SNES, SNESInitialGuessFn *, void *);
536: PETSC_EXTERN PetscErrorCode SNESSetPicard(SNES, Vec, SNESFunctionFn *, Mat, Mat, SNESJacobianFn *, void *);
537: PETSC_EXTERN PetscErrorCode SNESGetPicard(SNES, Vec *, SNESFunctionFn **, Mat *, Mat *, SNESJacobianFn **, void **);
538: PETSC_EXTERN SNESFunctionFn SNESPicardComputeFunction;
539: PETSC_EXTERN SNESFunctionFn SNESPicardComputeMFFunction;
540: PETSC_EXTERN SNESJacobianFn SNESPicardComputeJacobian;

542: PETSC_EXTERN PetscErrorCode SNESSetObjective(SNES, SNESObjectiveFn *, void *);
543: PETSC_EXTERN PetscErrorCode SNESGetObjective(SNES, SNESObjectiveFn **, void **);
544: PETSC_EXTERN PetscErrorCode SNESComputeObjective(SNES, Vec, PetscReal *);

546: PETSC_EXTERN PetscErrorCode SNESSetUpdate(SNES, SNESUpdateFn *);

548: /*E
549:    SNESNormSchedule - Frequency with which the norm is computed during a nonliner solve

551:    Values:
552: +   `SNES_NORM_DEFAULT`            - use the default behavior for the current `SNESType`
553: .   `SNES_NORM_NONE`               - avoid all norm computations
554: .   `SNES_NORM_ALWAYS`             - compute the norms whenever possible
555: .   `SNES_NORM_INITIAL_ONLY`       - compute the norm only when the algorithm starts
556: .   `SNES_NORM_FINAL_ONLY`         - compute the norm only when the algorithm finishes
557: -   `SNES_NORM_INITIAL_FINAL_ONLY` - compute the norm at the start and end of the algorithm

559:    Level: advanced

561:    Notes:
562:    Support for these is highly dependent on the solver.

564:    Some options limit the convergence tests that can be used.

566:    The `SNES_NORM_NONE` option is most commonly used when the nonlinear solver is being used as a smoother, for example for `SNESFAS`

568:    This is primarily used to turn off extra norm and function computation
569:    when the solvers are composed.

571: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `KSPSetNormType()`,
572:           `KSPSetConvergenceTest()`, `KSPSetPCSide()`
573: E*/
574: typedef enum {
575:   SNES_NORM_DEFAULT            = -1,
576:   SNES_NORM_NONE               = 0,
577:   SNES_NORM_ALWAYS             = 1,
578:   SNES_NORM_INITIAL_ONLY       = 2,
579:   SNES_NORM_FINAL_ONLY         = 3,
580:   SNES_NORM_INITIAL_FINAL_ONLY = 4
581: } SNESNormSchedule;
582: PETSC_EXTERN const char *const *const SNESNormSchedules;

584: /*MC
585:    SNES_NORM_NONE - Don't compute function and its L2 norm when possible

587:    Level: advanced

589:    Note:
590:    This is most useful for stationary solvers with a fixed number of iterations used as smoothers.

592: .seealso: [](ch_snes), `SNESNormSchedule`, `SNES`, `SNESSetNormSchedule()`, `SNES_NORM_DEFAULT`
593: M*/

595: /*MC
596:    SNES_NORM_ALWAYS - Compute the function and its L2 norm at each iteration.

598:    Level: advanced

600:    Note:
601:    Most solvers will use this no matter what norm type is passed to them.

603: .seealso: [](ch_snes), `SNESNormSchedule`, `SNES`, `SNESSetNormSchedule()`, `SNES_NORM_NONE`
604: M*/

606: /*MC
607:    SNES_NORM_INITIAL_ONLY - Compute the function and its L2 at iteration 0, but do not update it.

609:    Level: advanced

611:    Notes:
612:    This method is useful in composed methods, when a true solution might actually be found before `SNESSolve()` is called.
613:    This option enables the solve to abort on the zeroth iteration if this is the case.

615:    For solvers that require the computation of the L2 norm of the function as part of the method, this merely cancels
616:    the norm computation at the last iteration (if possible).

618: .seealso: [](ch_snes), `SNESNormSchedule`, `SNES`, `SNESSetNormSchedule()`, `SNES_NORM_FINAL_ONLY`, `SNES_NORM_INITIAL_FINAL_ONLY`
619: M*/

621: /*MC
622:    SNES_NORM_FINAL_ONLY - Compute the function and its L2 norm on only the final iteration.

624:    Level: advanced

626:    Note:
627:    For solvers that require the computation of the L2 norm of the function as part of the method, behaves
628:    exactly as `SNES_NORM_DEFAULT`.  This method is useful when the function is gotten after `SNESSolve()` and
629:    used in subsequent computation for methods that do not need the norm computed during the rest of the
630:    solution procedure.

632: .seealso: [](ch_snes), `SNESNormSchedule`, `SNES`, `SNESSetNormSchedule()`, `SNES_NORM_INITIAL_ONLY`, `SNES_NORM_INITIAL_FINAL_ONLY`
633: M*/

635: /*MC
636:    SNES_NORM_INITIAL_FINAL_ONLY - Compute the function and its L2 norm on only the initial and final iterations.

638:    Level: advanced

640:    Note:
641:    This method combines the benefits of `SNES_NORM_INITIAL_ONLY` and `SNES_NORM_FINAL_ONLY`.

643: .seealso: [](ch_snes), `SNESNormSchedule`, `SNES`, `SNESSetNormSchedule()`, `SNES_NORM_SNES_NORM_INITIAL_ONLY`, `SNES_NORM_FINAL_ONLY`
644: M*/

646: PETSC_EXTERN PetscErrorCode SNESSetNormSchedule(SNES, SNESNormSchedule);
647: PETSC_EXTERN PetscErrorCode SNESGetNormSchedule(SNES, SNESNormSchedule *);
648: PETSC_EXTERN PetscErrorCode SNESSetFunctionNorm(SNES, PetscReal);
649: PETSC_EXTERN PetscErrorCode SNESGetFunctionNorm(SNES, PetscReal *);
650: PETSC_EXTERN PetscErrorCode SNESGetUpdateNorm(SNES, PetscReal *);
651: PETSC_EXTERN PetscErrorCode SNESGetSolutionNorm(SNES, PetscReal *);

653: /*E
654:    SNESFunctionType - Type of function computed

656:    Values:
657: +  `SNES_FUNCTION_DEFAULT`          - the default behavior for the current `SNESType`
658: .  `SNES_FUNCTION_UNPRECONDITIONED` - the original function provided
659: -  `SNES_FUNCTION_PRECONDITIONED`   - the modification of the function by the preconditioner

661:    Level: advanced

663:    Note:
664:    Support for these is dependent on the solver.

666: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `KSPSetNormType()`,
667:           `KSPSetConvergenceTest()`, `KSPSetPCSide()`
668: E*/
669: typedef enum {
670:   SNES_FUNCTION_DEFAULT          = -1,
671:   SNES_FUNCTION_UNPRECONDITIONED = 0,
672:   SNES_FUNCTION_PRECONDITIONED   = 1
673: } SNESFunctionType;
674: PETSC_EXTERN const char *const *const SNESFunctionTypes;

676: PETSC_EXTERN PetscErrorCode SNESSetFunctionType(SNES, SNESFunctionType);
677: PETSC_EXTERN PetscErrorCode SNESGetFunctionType(SNES, SNESFunctionType *);

679: PETSC_EXTERN PetscErrorCode SNESSetNGS(SNES, SNESNGSFn *, void *);
680: PETSC_EXTERN PetscErrorCode SNESGetNGS(SNES, SNESNGSFn **, void **);
681: PETSC_EXTERN PetscErrorCode SNESComputeNGS(SNES, Vec, Vec);

683: PETSC_EXTERN PetscErrorCode SNESNGSSetSweeps(SNES, PetscInt);
684: PETSC_EXTERN PetscErrorCode SNESNGSGetSweeps(SNES, PetscInt *);
685: PETSC_EXTERN PetscErrorCode SNESNGSSetTolerances(SNES, PetscReal, PetscReal, PetscReal, PetscInt);
686: PETSC_EXTERN PetscErrorCode SNESNGSGetTolerances(SNES, PetscReal *, PetscReal *, PetscReal *, PetscInt *);

688: PETSC_EXTERN PetscErrorCode SNESSetAlwaysComputesFinalResidual(SNES, PetscBool);
689: PETSC_EXTERN PetscErrorCode SNESGetAlwaysComputesFinalResidual(SNES, PetscBool *);

691: PETSC_EXTERN PetscErrorCode SNESShellGetContext(SNES, void *);
692: PETSC_EXTERN PetscErrorCode SNESShellSetContext(SNES, void *);
693: PETSC_EXTERN PetscErrorCode SNESShellSetSolve(SNES, PetscErrorCode (*)(SNES, Vec));

695: /* --------- Routines specifically for line search methods --------------- */

697: /*S
698:    SNESLineSearch - Abstract PETSc object that manages line-search operations for nonlinear solvers

700:    Level: beginner

702: .seealso: [](ch_snes), `SNESLineSearchType`, `SNESLineSearchCreate()`, `SNESLineSearchSetType()`, `SNES`
703: S*/
704: typedef struct _p_LineSearch *SNESLineSearch;

706: /*J
707:    SNESLineSearchType - String with the name of a PETSc line search method `SNESLineSearch`

709:    Values:
710: +  `SNESLINESEARCHBASIC`   - (or equivalently `SNESLINESEARCHNONE`) Simple damping line search, defaults to using the full Newton step
711: .  `SNESLINESEARCHBT`      - Backtracking line search over the L2 norm of the function
712: .  `SNESLINESEARCHL2`      - Secant line search over the L2 norm of the function
713: .  `SNESLINESEARCHCP`      - Critical point secant line search assuming F(x) = grad G(x) for some unknown G(x)
714: .  `SNESLINESEARCHNLEQERR` - Affine-covariant error-oriented linesearch
715: -  `SNESLINESEARCHSHELL`   - User provided `SNESLineSearch` implementation

717:    Level: beginner

719: .seealso: [](ch_snes), `SNESLineSearch`, `SNESLineSearchSetType()`, `SNES`
720: J*/
721: typedef const char *SNESLineSearchType;
722: #define SNESLINESEARCHBT        "bt"
723: #define SNESLINESEARCHNLEQERR   "nleqerr"
724: #define SNESLINESEARCHBASIC     "basic"
725: #define SNESLINESEARCHNONE      "none"
726: #define SNESLINESEARCHL2        "l2"
727: #define SNESLINESEARCHCP        "cp"
728: #define SNESLINESEARCHSHELL     "shell"
729: #define SNESLINESEARCHNCGLINEAR "ncglinear"
730: #define SNESLINESEARCHBISECTION "bisection"

732: PETSC_EXTERN PetscFunctionList SNESList;
733: PETSC_EXTERN PetscClassId      SNESLINESEARCH_CLASSID;
734: PETSC_EXTERN PetscFunctionList SNESLineSearchList;

736: #define SNES_LINESEARCH_ORDER_LINEAR    1
737: #define SNES_LINESEARCH_ORDER_QUADRATIC 2
738: #define SNES_LINESEARCH_ORDER_CUBIC     3

740: /*S
741:   SNESLineSearchVIProjectFn - A prototype of a `SNES` function that projects a vector onto the VI bounds, passed to `SNESLineSearchSetVIFunctions()`

743:   Calling Sequence:
744: + snes  - `SNES` context
745: - u     - the vector to project to the bounds

747:   Level: advanced

749:   Note:
750:   The deprecated `SNESLineSearchVIProjectFunc` still works as a replacement for `SNESLineSearchVIProjectFn` *.

752: .seealso: [](ch_snes), `SNES`, `SNESLineSearch`
753: S*/
754: PETSC_EXTERN_TYPEDEF typedef PetscErrorCode(SNESLineSearchVIProjectFn)(SNES snes, Vec u);
755: PETSC_EXTERN_TYPEDEF typedef SNESLineSearchVIProjectFn *SNESLineSearchVIProjectFunc; // deprecated

757: /*S
758:   SNESLineSearchVIProjectFn - A prototype of a `SNES` function that computes the norm of the active set variables in a vector in a VI solve,
759:   passed to `SNESLineSearchSetVIFunctions()`

761:   Calling Sequence:
762: + snes  - `SNES` context
763: . f     - the vector to compute the norm of
764: . u     - the current solution, entries that are on the VI bounds are ignored
765: - fnorm - the resulting norm

767:   Level: advanced

769:   Note:
770:   The deprecated `SNESLineSearchVINormFunc` still works as a replacement for `SNESLineSearchVINormFn` *.

772: .seealso: [](ch_snes), `SNES`, `SNESLineSearch`
773: S*/
774: PETSC_EXTERN_TYPEDEF typedef PetscErrorCode(SNESLineSearchVINormFn)(SNES snes, Vec f, Vec u, PetscReal *fnorm);
775: PETSC_EXTERN_TYPEDEF typedef SNESLineSearchVINormFn *SNESLineSearchVINormFunc; // deprecated

777: PETSC_EXTERN_TYPEDEF typedef PetscErrorCode(SNESLineSearchApplyFn)(SNESLineSearch);
778: PETSC_EXTERN_TYPEDEF typedef SNESLineSearchApplyFn *SNESLineSearchApplyFunc; // deprecated
779: PETSC_EXTERN_TYPEDEF typedef PetscErrorCode(SNESLineSearchShellApplyFn)(SNESLineSearch, void *);
780: PETSC_EXTERN_TYPEDEF typedef SNESLineSearchShellApplyFn *SNESLineSearchUserFunc; // deprecated

782: PETSC_EXTERN PetscErrorCode SNESLineSearchCreate(MPI_Comm, SNESLineSearch *);
783: PETSC_EXTERN PetscErrorCode SNESLineSearchReset(SNESLineSearch);
784: PETSC_EXTERN PetscErrorCode SNESLineSearchView(SNESLineSearch, PetscViewer);
785: PETSC_EXTERN PetscErrorCode SNESLineSearchDestroy(SNESLineSearch *);
786: PETSC_EXTERN PetscErrorCode SNESLineSearchGetType(SNESLineSearch, SNESLineSearchType *);
787: PETSC_EXTERN PetscErrorCode SNESLineSearchSetType(SNESLineSearch, SNESLineSearchType);
788: PETSC_EXTERN PetscErrorCode SNESLineSearchSetFromOptions(SNESLineSearch);
789: PETSC_EXTERN PetscErrorCode SNESLineSearchSetFunction(SNESLineSearch, PetscErrorCode (*)(SNES, Vec, Vec));
790: PETSC_EXTERN PetscErrorCode SNESLineSearchSetUp(SNESLineSearch);
791: PETSC_EXTERN PetscErrorCode SNESLineSearchApply(SNESLineSearch, Vec, Vec, PetscReal *, Vec);
792: PETSC_EXTERN PetscErrorCode SNESLineSearchPreCheck(SNESLineSearch, Vec, Vec, PetscBool *);
793: PETSC_EXTERN PetscErrorCode SNESLineSearchPostCheck(SNESLineSearch, Vec, Vec, Vec, PetscBool *, PetscBool *);
794: PETSC_EXTERN PetscErrorCode SNESLineSearchSetWorkVecs(SNESLineSearch, PetscInt);

796: /* set the functions for precheck and postcheck */

798: PETSC_EXTERN PetscErrorCode SNESLineSearchSetPreCheck(SNESLineSearch, PetscErrorCode (*)(SNESLineSearch, Vec, Vec, PetscBool *, void *), void *ctx);
799: PETSC_EXTERN PetscErrorCode SNESLineSearchSetPostCheck(SNESLineSearch, PetscErrorCode (*)(SNESLineSearch, Vec, Vec, Vec, PetscBool *, PetscBool *, void *), void *ctx);

801: PETSC_EXTERN PetscErrorCode SNESLineSearchGetPreCheck(SNESLineSearch, PetscErrorCode (**)(SNESLineSearch, Vec, Vec, PetscBool *, void *), void **ctx);
802: PETSC_EXTERN PetscErrorCode SNESLineSearchGetPostCheck(SNESLineSearch, PetscErrorCode (**)(SNESLineSearch, Vec, Vec, Vec, PetscBool *, PetscBool *, void *), void **ctx);

804: /* set the functions for VI-specific line search operations */

806: PETSC_EXTERN PetscErrorCode SNESLineSearchSetVIFunctions(SNESLineSearch, SNESLineSearchVIProjectFn *, SNESLineSearchVINormFn *);
807: PETSC_EXTERN PetscErrorCode SNESLineSearchGetVIFunctions(SNESLineSearch, SNESLineSearchVIProjectFn **, SNESLineSearchVINormFn **);

809: /* pointers to the associated SNES in order to be able to get the function evaluation out */
810: PETSC_EXTERN PetscErrorCode SNESLineSearchSetSNES(SNESLineSearch, SNES);
811: PETSC_EXTERN PetscErrorCode SNESLineSearchGetSNES(SNESLineSearch, SNES *);

813: /* set and get the parameters and vectors */
814: PETSC_EXTERN PetscErrorCode SNESLineSearchGetTolerances(SNESLineSearch, PetscReal *, PetscReal *, PetscReal *, PetscReal *, PetscReal *, PetscInt *);
815: PETSC_EXTERN PetscErrorCode SNESLineSearchSetTolerances(SNESLineSearch, PetscReal, PetscReal, PetscReal, PetscReal, PetscReal, PetscInt);

817: PETSC_EXTERN PetscErrorCode SNESLineSearchPreCheckPicard(SNESLineSearch, Vec, Vec, PetscBool *, void *);

819: PETSC_EXTERN PetscErrorCode SNESLineSearchGetLambda(SNESLineSearch, PetscReal *);
820: PETSC_EXTERN PetscErrorCode SNESLineSearchSetLambda(SNESLineSearch, PetscReal);

822: PETSC_EXTERN PetscErrorCode SNESLineSearchGetDamping(SNESLineSearch, PetscReal *);
823: PETSC_EXTERN PetscErrorCode SNESLineSearchSetDamping(SNESLineSearch, PetscReal);

825: PETSC_EXTERN PetscErrorCode SNESLineSearchGetOrder(SNESLineSearch, PetscInt *order);
826: PETSC_EXTERN PetscErrorCode SNESLineSearchSetOrder(SNESLineSearch, PetscInt order);

828: /*E
829:     SNESLineSearchReason - indication if the line search has succeeded or failed and why

831:   Values:
832: +  `SNES_LINESEARCH_SUCCEEDED`       - the line search succeeded
833: .  `SNES_LINESEARCH_FAILED_NANORINF` - a not a number of infinity appeared in the computions
834: .  `SNES_LINESEARCH_FAILED_DOMAIN`   - the function was evaluated outside of its domain, see `SNESSetFunctionDomainError()` and `SNESSetJacobianDomainError()`
835: .  `SNES_LINESEARCH_FAILED_REDUCT`   - the linear search failed to get the requested decrease in its norm or objective
836: .  `SNES_LINESEARCH_FAILED_USER`     - used by `SNESLINESEARCHNLEQERR` to indicate the user changed the search direction inappropriately
837: -  `SNES_LINESEARCH_FAILED_FUNCTION` - indicates the maximum number of function evaluations allowed has been surpassed, `SNESConvergedReason` is also
838:                                        set to `SNES_DIVERGED_FUNCTION_COUNT`

840:    Level: intermediate

842:    Developer Note:
843:    Some of these reasons overlap with values of `SNESConvergedReason`

845: .seealso: [](ch_snes), `SNES`, `SNESSolve()`, `SNESGetConvergedReason()`, `KSPConvergedReason`, `SNESSetConvergenceTest()`,
846:           `SNESSetFunctionDomainError()` and `SNESSetJacobianDomainError()`
847: E*/
848: typedef enum {
849:   SNES_LINESEARCH_SUCCEEDED,
850:   SNES_LINESEARCH_FAILED_NANORINF,
851:   SNES_LINESEARCH_FAILED_DOMAIN,
852:   SNES_LINESEARCH_FAILED_REDUCT, /* INSUFFICIENT REDUCTION */
853:   SNES_LINESEARCH_FAILED_USER,
854:   SNES_LINESEARCH_FAILED_FUNCTION
855: } SNESLineSearchReason;

857: PETSC_EXTERN PetscErrorCode SNESLineSearchGetReason(SNESLineSearch, SNESLineSearchReason *);
858: PETSC_EXTERN PetscErrorCode SNESLineSearchSetReason(SNESLineSearch, SNESLineSearchReason);

860: PETSC_EXTERN PetscErrorCode SNESLineSearchGetVecs(SNESLineSearch, Vec *, Vec *, Vec *, Vec *, Vec *);
861: PETSC_EXTERN PetscErrorCode SNESLineSearchSetVecs(SNESLineSearch, Vec, Vec, Vec, Vec, Vec);

863: PETSC_EXTERN PetscErrorCode SNESLineSearchGetNorms(SNESLineSearch, PetscReal *, PetscReal *, PetscReal *);
864: PETSC_EXTERN PetscErrorCode SNESLineSearchSetNorms(SNESLineSearch, PetscReal, PetscReal, PetscReal);
865: PETSC_EXTERN PetscErrorCode SNESLineSearchComputeNorms(SNESLineSearch);
866: PETSC_EXTERN PetscErrorCode SNESLineSearchSetComputeNorms(SNESLineSearch, PetscBool);

868: PETSC_EXTERN PetscErrorCode SNESLineSearchMonitor(SNESLineSearch);
869: PETSC_EXTERN PetscErrorCode SNESLineSearchMonitorSet(SNESLineSearch, PetscErrorCode (*)(SNESLineSearch, void *), void *, PetscCtxDestroyFn *);
870: PETSC_EXTERN PetscErrorCode SNESLineSearchMonitorSetFromOptions(SNESLineSearch, const char[], const char[], const char[], PetscErrorCode (*)(SNESLineSearch, PetscViewerAndFormat *), PetscErrorCode (*)(SNESLineSearch, PetscViewerAndFormat *));
871: PETSC_EXTERN PetscErrorCode SNESLineSearchMonitorCancel(SNESLineSearch);
872: PETSC_EXTERN PetscErrorCode SNESLineSearchSetDefaultMonitor(SNESLineSearch, PetscViewer);
873: PETSC_EXTERN PetscErrorCode SNESLineSearchGetDefaultMonitor(SNESLineSearch, PetscViewer *);
874: PETSC_EXTERN PetscErrorCode SNESLineSearchMonitorSolutionUpdate(SNESLineSearch, PetscViewerAndFormat *);

876: PETSC_EXTERN PetscErrorCode SNESLineSearchAppendOptionsPrefix(SNESLineSearch, const char prefix[]);
877: PETSC_EXTERN PetscErrorCode SNESLineSearchGetOptionsPrefix(SNESLineSearch, const char *prefix[]);

879: /* Shell interface functions */
880: PETSC_EXTERN PetscErrorCode SNESLineSearchShellSetApply(SNESLineSearch, SNESLineSearchShellApplyFn, void *);
881: PETSC_EXTERN PetscErrorCode SNESLineSearchShellGetApply(SNESLineSearch, SNESLineSearchShellApplyFn **, void **);

883: PETSC_DEPRECATED_FUNCTION(3, 21, 0, "SNESLinesearchShellSetApply()", ) static inline PetscErrorCode SNESLineSearchShellSetUserFunc(SNESLineSearch ls, SNESLineSearchUserFunc f, void *ctx)
884: {
885:   return SNESLineSearchShellSetApply(ls, f, ctx);
886: }

888: PETSC_DEPRECATED_FUNCTION(3, 21, 0, "SNESLinesearchShellGetApply()", ) static inline PetscErrorCode SNESLineSearchShellGetUserFunc(SNESLineSearch ls, SNESLineSearchUserFunc *f, void **ctx)
889: {
890:   return SNESLineSearchShellGetApply(ls, f, ctx);
891: }

893: /* BT interface functions */
894: PETSC_EXTERN PetscErrorCode SNESLineSearchBTSetAlpha(SNESLineSearch, PetscReal);
895: PETSC_EXTERN PetscErrorCode SNESLineSearchBTGetAlpha(SNESLineSearch, PetscReal *);

897: /*register line search types */
898: PETSC_EXTERN PetscErrorCode SNESLineSearchRegister(const char[], PetscErrorCode (*)(SNESLineSearch));

900: /* Routines for VI solver */
901: PETSC_EXTERN PetscErrorCode SNESVISetVariableBounds(SNES, Vec, Vec);
902: PETSC_EXTERN PetscErrorCode SNESVIGetVariableBounds(SNES, Vec *, Vec *);
903: PETSC_EXTERN PetscErrorCode SNESVISetComputeVariableBounds(SNES, PetscErrorCode (*)(SNES, Vec, Vec));
904: PETSC_EXTERN PetscErrorCode SNESVIGetInactiveSet(SNES, IS *);
905: PETSC_EXTERN PetscErrorCode SNESVIGetActiveSetIS(SNES, Vec, Vec, IS *);
906: PETSC_EXTERN PetscErrorCode SNESVIComputeInactiveSetFnorm(SNES, Vec, Vec, PetscReal *);
907: PETSC_EXTERN PetscErrorCode SNESVISetRedundancyCheck(SNES, PetscErrorCode (*)(SNES, IS, IS *, void *), void *);
908: PETSC_EXTERN PetscErrorCode SNESVIComputeMeritFunction(Vec, PetscReal *, PetscReal *);
909: PETSC_EXTERN PetscErrorCode SNESVIComputeFunction(SNES, Vec, Vec, void *);
910: PETSC_EXTERN PetscErrorCode DMSetVI(DM, IS);
911: PETSC_EXTERN PetscErrorCode DMDestroyVI(DM);

913: PETSC_EXTERN PetscErrorCode SNESTestLocalMin(SNES);

915: /* Should this routine be private? */
916: PETSC_EXTERN PetscErrorCode SNESComputeJacobian(SNES, Vec, Mat, Mat);
917: PETSC_EXTERN PetscErrorCode SNESTestJacobian(SNES);
918: PETSC_EXTERN PetscErrorCode SNESTestFunction(SNES);

920: PETSC_EXTERN PetscErrorCode SNESSetDM(SNES, DM);
921: PETSC_EXTERN PetscErrorCode SNESGetDM(SNES, DM *);
922: PETSC_EXTERN PetscErrorCode SNESSetNPC(SNES, SNES);
923: PETSC_EXTERN PetscErrorCode SNESGetNPC(SNES, SNES *);
924: PETSC_EXTERN PetscErrorCode SNESHasNPC(SNES, PetscBool *);
925: PETSC_EXTERN PetscErrorCode SNESApplyNPC(SNES, Vec, Vec, Vec);
926: PETSC_EXTERN PetscErrorCode SNESGetNPCFunction(SNES, Vec, PetscReal *);
927: PETSC_EXTERN PetscErrorCode SNESComputeFunctionDefaultNPC(SNES, Vec, Vec);
928: PETSC_EXTERN PetscErrorCode SNESSetNPCSide(SNES, PCSide);
929: PETSC_EXTERN PetscErrorCode SNESGetNPCSide(SNES, PCSide *);
930: PETSC_EXTERN PetscErrorCode SNESSetLineSearch(SNES, SNESLineSearch);
931: PETSC_EXTERN PetscErrorCode SNESGetLineSearch(SNES, SNESLineSearch *);

933: PETSC_DEPRECATED_FUNCTION(3, 4, 0, "SNESGetLineSearch()", ) static inline PetscErrorCode SNESGetSNESLineSearch(SNES snes, SNESLineSearch *ls)
934: {
935:   return SNESGetLineSearch(snes, ls);
936: }
937: PETSC_DEPRECATED_FUNCTION(3, 4, 0, "SNESSetLineSearch()", ) static inline PetscErrorCode SNESSetSNESLineSearch(SNES snes, SNESLineSearch ls)
938: {
939:   return SNESSetLineSearch(snes, ls);
940: }

942: PETSC_EXTERN PetscErrorCode SNESSetUpMatrices(SNES);
943: PETSC_EXTERN PetscErrorCode DMSNESSetFunction(DM, SNESFunctionFn *, void *);
944: PETSC_EXTERN PetscErrorCode DMSNESGetFunction(DM, SNESFunctionFn **, void **);
945: PETSC_EXTERN PetscErrorCode DMSNESSetFunctionContextDestroy(DM, PetscCtxDestroyFn *);
946: PETSC_EXTERN PetscErrorCode DMSNESSetMFFunction(DM, SNESFunctionFn *, void *);
947: PETSC_EXTERN PetscErrorCode DMSNESSetNGS(DM, SNESNGSFn *, void *);
948: PETSC_EXTERN PetscErrorCode DMSNESGetNGS(DM, SNESNGSFn **, void **);
949: PETSC_EXTERN PetscErrorCode DMSNESSetJacobian(DM, SNESJacobianFn *, void *);
950: PETSC_EXTERN PetscErrorCode DMSNESGetJacobian(DM, SNESJacobianFn **, void **);
951: PETSC_EXTERN PetscErrorCode DMSNESSetJacobianContextDestroy(DM, PetscCtxDestroyFn *);
952: PETSC_EXTERN PetscErrorCode DMSNESSetPicard(DM, SNESFunctionFn *, SNESJacobianFn *, void *);
953: PETSC_EXTERN PetscErrorCode DMSNESGetPicard(DM, SNESFunctionFn **, SNESJacobianFn **, void **);
954: PETSC_EXTERN PetscErrorCode DMSNESSetObjective(DM, SNESObjectiveFn *, void *);
955: PETSC_EXTERN PetscErrorCode DMSNESGetObjective(DM, SNESObjectiveFn **, void **);
956: PETSC_EXTERN PetscErrorCode DMCopyDMSNES(DM, DM);

958: PETSC_EXTERN_TYPEDEF typedef PetscErrorCode(DMDASNESFunctionFn)(DMDALocalInfo *, void *, void *, void *);
959: PETSC_EXTERN_TYPEDEF typedef PetscErrorCode(DMDASNESJacobianFn)(DMDALocalInfo *, void *, Mat, Mat, void *);
960: PETSC_EXTERN_TYPEDEF typedef PetscErrorCode(DMDASNESObjectiveFn)(DMDALocalInfo *, void *, PetscReal *, void *);

962: PETSC_EXTERN_TYPEDEF typedef PetscErrorCode(DMDASNESFunctionVecFn)(DMDALocalInfo *, Vec, Vec, void *);
963: PETSC_EXTERN_TYPEDEF typedef PetscErrorCode(DMDASNESJacobianVecFn)(DMDALocalInfo *, Vec, Mat, Mat, void *);
964: PETSC_EXTERN_TYPEDEF typedef PetscErrorCode(DMDASNESObjectiveVecFn)(DMDALocalInfo *, Vec, PetscReal *, void *);

966: PETSC_EXTERN PetscErrorCode DMDASNESSetFunctionLocal(DM, InsertMode, DMDASNESFunctionFn *, void *);
967: PETSC_EXTERN PetscErrorCode DMDASNESSetJacobianLocal(DM, DMDASNESJacobianFn *, void *);
968: PETSC_EXTERN PetscErrorCode DMDASNESSetObjectiveLocal(DM, DMDASNESObjectiveFn *, void *);
969: PETSC_EXTERN PetscErrorCode DMDASNESSetPicardLocal(DM, InsertMode, DMDASNESFunctionFn *, DMDASNESJacobianFn, void *);

971: PETSC_EXTERN PetscErrorCode DMDASNESSetFunctionLocalVec(DM, InsertMode, DMDASNESFunctionVecFn *, void *);
972: PETSC_EXTERN PetscErrorCode DMDASNESSetJacobianLocalVec(DM, DMDASNESJacobianVecFn *, void *);
973: PETSC_EXTERN PetscErrorCode DMDASNESSetObjectiveLocalVec(DM, DMDASNESObjectiveVecFn *, void *);

975: PETSC_EXTERN PetscErrorCode DMSNESSetBoundaryLocal(DM, PetscErrorCode (*)(DM, Vec, void *), void *);
976: PETSC_EXTERN PetscErrorCode DMSNESSetObjectiveLocal(DM, PetscErrorCode (*)(DM, Vec, PetscReal *, void *), void *);
977: PETSC_EXTERN PetscErrorCode DMSNESSetFunctionLocal(DM, PetscErrorCode (*)(DM, Vec, Vec, void *), void *);
978: PETSC_EXTERN PetscErrorCode DMSNESSetJacobianLocal(DM, PetscErrorCode (*)(DM, Vec, Mat, Mat, void *), void *);
979: PETSC_EXTERN PetscErrorCode DMSNESGetBoundaryLocal(DM, PetscErrorCode (**)(DM, Vec, void *), void **);
980: PETSC_EXTERN PetscErrorCode DMSNESGetObjectiveLocal(DM, PetscErrorCode (**)(DM, Vec, PetscReal *, void *), void **);
981: PETSC_EXTERN PetscErrorCode DMSNESGetFunctionLocal(DM, PetscErrorCode (**)(DM, Vec, Vec, void *), void **);
982: PETSC_EXTERN PetscErrorCode DMSNESGetJacobianLocal(DM, PetscErrorCode (**)(DM, Vec, Mat, Mat, void *), void **);

984: /* Routines for Multiblock solver */
985: PETSC_EXTERN PetscErrorCode SNESMultiblockSetFields(SNES, const char[], PetscInt, const PetscInt *);
986: PETSC_EXTERN PetscErrorCode SNESMultiblockSetIS(SNES, const char[], IS);
987: PETSC_EXTERN PetscErrorCode SNESMultiblockSetBlockSize(SNES, PetscInt);
988: PETSC_EXTERN PetscErrorCode SNESMultiblockSetType(SNES, PCCompositeType);
989: PETSC_EXTERN PetscErrorCode SNESMultiblockGetSubSNES(SNES, PetscInt *, SNES *[]);

991: /*J
992:    SNESMSType - String with the name of a PETSc `SNESMS` method.

994:    Level: intermediate

996: .seealso: [](ch_snes), `SNESMS`, `SNESMSGetType()`, `SNESMSSetType()`, `SNES`
997: J*/
998: typedef const char *SNESMSType;
999: #define SNESMSM62       "m62"
1000: #define SNESMSEULER     "euler"
1001: #define SNESMSJAMESON83 "jameson83"
1002: #define SNESMSVLTP11    "vltp11"
1003: #define SNESMSVLTP21    "vltp21"
1004: #define SNESMSVLTP31    "vltp31"
1005: #define SNESMSVLTP41    "vltp41"
1006: #define SNESMSVLTP51    "vltp51"
1007: #define SNESMSVLTP61    "vltp61"

1009: PETSC_EXTERN PetscErrorCode SNESMSRegister(SNESMSType, PetscInt, PetscInt, PetscReal, const PetscReal[], const PetscReal[], const PetscReal[]);
1010: PETSC_EXTERN PetscErrorCode SNESMSRegisterAll(void);
1011: PETSC_EXTERN PetscErrorCode SNESMSGetType(SNES, SNESMSType *);
1012: PETSC_EXTERN PetscErrorCode SNESMSSetType(SNES, SNESMSType);
1013: PETSC_EXTERN PetscErrorCode SNESMSGetDamping(SNES, PetscReal *);
1014: PETSC_EXTERN PetscErrorCode SNESMSSetDamping(SNES, PetscReal);
1015: PETSC_EXTERN PetscErrorCode SNESMSFinalizePackage(void);
1016: PETSC_EXTERN PetscErrorCode SNESMSInitializePackage(void);
1017: PETSC_EXTERN PetscErrorCode SNESMSRegisterDestroy(void);

1019: /*MC
1020:    SNESNGMRESRestartType - the restart approach used by `SNESNGMRES`

1022:   Values:
1023: +   `SNES_NGMRES_RESTART_NONE`       - never restart
1024: .   `SNES_NGMRES_RESTART_DIFFERENCE` - restart based upon difference criteria
1025: -   `SNES_NGMRES_RESTART_PERIODIC`   - restart after a fixed number of iterations

1027:   Options Database Keys:
1028: + -snes_ngmres_restart_type <difference,periodic,none> - set the restart type
1029: - -snes_ngmres_restart <30>                            - sets the number of iterations before restart for periodic

1031:    Level: intermediate

1033: .seealso: `SNES, `SNESNGMRES`, `SNESNGMRESSetSelectType()`, `SNESNGMRESGetSelectType()`, `SNESNGMRESSetRestartType()`,
1034:           `SNESNGMRESGetRestartType()`, `SNESNGMRESSelectType`
1035: M*/
1036: typedef enum {
1037:   SNES_NGMRES_RESTART_NONE       = 0,
1038:   SNES_NGMRES_RESTART_PERIODIC   = 1,
1039:   SNES_NGMRES_RESTART_DIFFERENCE = 2
1040: } SNESNGMRESRestartType;
1041: PETSC_EXTERN const char *const SNESNGMRESRestartTypes[];

1043: /*MC
1044:    SNESNGMRESSelectType - the approach used by `SNESNGMRES` to determine how the candidate solution and
1045:   combined solution are used to create the next iterate.

1047:    Values:
1048: +   `SNES_NGMRES_SELECT_NONE`       - choose the combined solution all the time
1049: .   `SNES_NGMRES_SELECT_DIFFERENCE` - choose based upon the selection criteria
1050: -   `SNES_NGMRES_SELECT_LINESEARCH` - choose based upon line search combination

1052:   Options Database Key:
1053: . -snes_ngmres_select_type<difference,none,linesearch> - select type

1055:    Level: intermediate

1057: .seealso: `SNES, `SNESNGMRES`, `SNESNGMRESSetSelectType()`, `SNESNGMRESGetSelectType()`, `SNESNGMRESSetRestartType()`,
1058:           `SNESNGMRESGetRestartType()`, `SNESNGMRESRestartType`
1059: M*/
1060: typedef enum {
1061:   SNES_NGMRES_SELECT_NONE       = 0,
1062:   SNES_NGMRES_SELECT_DIFFERENCE = 1,
1063:   SNES_NGMRES_SELECT_LINESEARCH = 2
1064: } SNESNGMRESSelectType;
1065: PETSC_EXTERN const char *const SNESNGMRESSelectTypes[];

1067: PETSC_EXTERN PetscErrorCode SNESNGMRESSetRestartType(SNES, SNESNGMRESRestartType);
1068: PETSC_EXTERN PetscErrorCode SNESNGMRESSetSelectType(SNES, SNESNGMRESSelectType);
1069: PETSC_EXTERN PetscErrorCode SNESNGMRESSetRestartFmRise(SNES, PetscBool);
1070: PETSC_EXTERN PetscErrorCode SNESNGMRESGetRestartFmRise(SNES, PetscBool *);

1072: /*MC
1073:    SNESNCGType - the conjugate update approach for `SNESNCG`

1075:    Values:
1076: +   `SNES_NCG_FR`  - Fletcher-Reeves update
1077: .   `SNES_NCG_PRP` - Polak-Ribiere-Polyak update, the default and the only one that tolerates generalized search directions
1078: .   `SNES_NCG_HS`  - Hestenes-Steifel update
1079: .   `SNES_NCG_DY`  - Dai-Yuan update
1080: -   `SNES_NCG_CD`  - Conjugate Descent update

1082:   Options Database Key:
1083: . -snes_ncg_type<fr,prp,hs,dy,cd> - select type

1085:    Level: intermediate

1087: .seealso: `SNES, `SNESNCG`, `SNESNCGSetType()`
1088: M*/
1089: typedef enum {
1090:   SNES_NCG_FR  = 0,
1091:   SNES_NCG_PRP = 1,
1092:   SNES_NCG_HS  = 2,
1093:   SNES_NCG_DY  = 3,
1094:   SNES_NCG_CD  = 4
1095: } SNESNCGType;
1096: PETSC_EXTERN const char *const SNESNCGTypes[];

1098: PETSC_EXTERN PetscErrorCode SNESNCGSetType(SNES, SNESNCGType);

1100: /*MC
1101:    SNESQNScaleType - the scaling type used by `SNESQN`

1103:    Values:
1104: +   `SNES_QN_SCALE_NONE`     - don't scale the problem
1105: .   `SNES_QN_SCALE_SCALAR`   - use Shanno scaling
1106: .   `SNES_QN_SCALE_DIAGONAL` - scale with a diagonalized BFGS formula (see Gilbert and Lemarechal 1989), available
1107: -   `SNES_QN_SCALE_JACOBIAN` - scale by solving a linear system coming from the Jacobian you provided with `SNESSetJacobian()`
1108:                                computed at the first iteration of `SNESQN` and at ever restart.

1110:     Options Database Key:
1111: . -snes_qn_scale_type <diagonal,none,scalar,jacobian> - Scaling type

1113:    Level: intermediate

1115: .seealso: `SNES, `SNESQN`, `SNESQNSetScaleType()`, `SNESQNType`, `SNESQNSetType()`, `SNESQNSetRestartType()`, `SNESQNRestartType`
1116: M*/
1117: typedef enum {
1118:   SNES_QN_SCALE_DEFAULT  = 0,
1119:   SNES_QN_SCALE_NONE     = 1,
1120:   SNES_QN_SCALE_SCALAR   = 2,
1121:   SNES_QN_SCALE_DIAGONAL = 3,
1122:   SNES_QN_SCALE_JACOBIAN = 4
1123: } SNESQNScaleType;
1124: PETSC_EXTERN const char *const SNESQNScaleTypes[];

1126: /*MC
1127:    SNESQNRestartType - the restart approached used by `SNESQN`

1129:    Values:
1130: +   `SNES_QN_RESTART_NONE`     - never restart
1131: .   `SNES_QN_RESTART_POWELL`   - restart based upon descent criteria
1132: -   `SNES_QN_RESTART_PERIODIC` - restart after a fixed number of iterations

1134:   Options Database Keys:
1135: + -snes_qn_restart_type <powell,periodic,none> - set the restart type
1136: - -snes_qn_m <m>                               - sets the number of stored updates and the restart period for periodic

1138:    Level: intermediate

1140: .seealso: `SNES, `SNESQN`, `SNESQNSetScaleType()`, `SNESQNType`, `SNESQNSetType()`, `SNESQNSetRestartType()`, `SNESQNScaleType`
1141: M*/
1142: typedef enum {
1143:   SNES_QN_RESTART_DEFAULT  = 0,
1144:   SNES_QN_RESTART_NONE     = 1,
1145:   SNES_QN_RESTART_POWELL   = 2,
1146:   SNES_QN_RESTART_PERIODIC = 3
1147: } SNESQNRestartType;
1148: PETSC_EXTERN const char *const SNESQNRestartTypes[];

1150: /*MC
1151:    SNESQNType - the type used by `SNESQN`

1153:   Values:
1154: +   `SNES_QN_LBFGS`      - LBFGS variant
1155: .   `SNES_QN_BROYDEN`    - Broyden variant
1156: -   `SNES_QN_BADBROYDEN` - Bad Broyden variant

1158:   Options Database Key:
1159: . -snes_qn_type <lbfgs,broyden,badbroyden> - quasi-Newton type

1161:    Level: intermediate

1163: .seealso: `SNES, `SNESQN`, `SNESQNSetScaleType()`, `SNESQNSetType()`, `SNESQNScaleType`, `SNESQNRestartType`, `SNESQNSetRestartType()`
1164: M*/
1165: typedef enum {
1166:   SNES_QN_LBFGS      = 0,
1167:   SNES_QN_BROYDEN    = 1,
1168:   SNES_QN_BADBROYDEN = 2
1169: } SNESQNType;
1170: PETSC_EXTERN const char *const SNESQNTypes[];

1172: PETSC_EXTERN PetscErrorCode SNESQNSetType(SNES, SNESQNType);
1173: PETSC_EXTERN PetscErrorCode SNESQNSetScaleType(SNES, SNESQNScaleType);
1174: PETSC_EXTERN PetscErrorCode SNESQNSetRestartType(SNES, SNESQNRestartType);

1176: PETSC_EXTERN PetscErrorCode SNESNASMGetType(SNES, PCASMType *);
1177: PETSC_EXTERN PetscErrorCode SNESNASMSetType(SNES, PCASMType);
1178: PETSC_EXTERN PetscErrorCode SNESNASMGetSubdomains(SNES, PetscInt *, SNES **, VecScatter **, VecScatter **, VecScatter **);
1179: PETSC_EXTERN PetscErrorCode SNESNASMSetSubdomains(SNES, PetscInt, SNES *, VecScatter *, VecScatter *, VecScatter *);
1180: PETSC_EXTERN PetscErrorCode SNESNASMSetDamping(SNES, PetscReal);
1181: PETSC_EXTERN PetscErrorCode SNESNASMGetDamping(SNES, PetscReal *);
1182: PETSC_EXTERN PetscErrorCode SNESNASMGetSubdomainVecs(SNES, PetscInt *, Vec **, Vec **, Vec **, Vec **);
1183: PETSC_EXTERN PetscErrorCode SNESNASMSetComputeFinalJacobian(SNES, PetscBool);
1184: PETSC_EXTERN PetscErrorCode SNESNASMGetSNES(SNES, PetscInt, SNES *);
1185: PETSC_EXTERN PetscErrorCode SNESNASMGetNumber(SNES, PetscInt *);
1186: PETSC_EXTERN PetscErrorCode SNESNASMSetWeight(SNES, Vec);

1188: /*E
1189:   SNESCompositeType - Determines how two or more preconditioners are composed with the `SNESType` of `SNESCOMPOSITE`

1191:   Values:
1192: + `SNES_COMPOSITE_ADDITIVE`        - results from application of all preconditioners are added together
1193: . `SNES_COMPOSITE_MULTIPLICATIVE`  - preconditioners are applied sequentially to the residual freshly
1194:                                      computed after the previous preconditioner application
1195: - `SNES_COMPOSITE_ADDITIVEOPTIMAL` - uses a linear combination of the solutions obtained with each preconditioner that approximately minimize the function
1196:                                      value at the new iteration.

1198:    Level: beginner

1200: .seealso: [](sec_pc), `PCCOMPOSITE`, `PCFIELDSPLIT`, `PC`, `PCCompositeSetType()`, `PCCompositeType`
1201: E*/
1202: typedef enum {
1203:   SNES_COMPOSITE_ADDITIVE,
1204:   SNES_COMPOSITE_MULTIPLICATIVE,
1205:   SNES_COMPOSITE_ADDITIVEOPTIMAL
1206: } SNESCompositeType;
1207: PETSC_EXTERN const char *const SNESCompositeTypes[];

1209: PETSC_EXTERN PetscErrorCode SNESCompositeSetType(SNES, SNESCompositeType);
1210: PETSC_EXTERN PetscErrorCode SNESCompositeAddSNES(SNES, SNESType);
1211: PETSC_EXTERN PetscErrorCode SNESCompositeGetSNES(SNES, PetscInt, SNES *);
1212: PETSC_EXTERN PetscErrorCode SNESCompositeGetNumber(SNES, PetscInt *);
1213: PETSC_EXTERN PetscErrorCode SNESCompositeSetDamping(SNES, PetscInt, PetscReal);

1215: PETSC_EXTERN PetscErrorCode SNESPatchSetDiscretisationInfo(SNES, PetscInt, DM *, PetscInt *, PetscInt *, const PetscInt **, const PetscInt *, PetscInt, const PetscInt *, PetscInt, const PetscInt *);
1216: PETSC_EXTERN PetscErrorCode SNESPatchSetComputeOperator(SNES, PetscErrorCode (*func)(PC, PetscInt, Vec, Mat, IS, PetscInt, const PetscInt *, const PetscInt *, void *), void *);
1217: PETSC_EXTERN PetscErrorCode SNESPatchSetComputeFunction(SNES, PetscErrorCode (*func)(PC, PetscInt, Vec, Vec, IS, PetscInt, const PetscInt *, const PetscInt *, void *), void *);
1218: PETSC_EXTERN PetscErrorCode SNESPatchSetConstructType(SNES, PCPatchConstructType, PetscErrorCode (*func)(PC, PetscInt *, IS **, IS *, void *), void *);
1219: PETSC_EXTERN PetscErrorCode SNESPatchSetCellNumbering(SNES, PetscSection);

1221: /*E
1222:     SNESFASType - Determines the type of nonlinear multigrid method that is run.

1224:    Values:
1225: +  `SNES_FAS_MULTIPLICATIVE` (default) - traditional V or W cycle as determined by `SNESFASSetCycles()`
1226: .  `SNES_FAS_ADDITIVE`                 - additive FAS cycle
1227: .  `SNES_FAS_FULL`                     - full FAS cycle
1228: -  `SNES_FAS_KASKADE`                  - Kaskade FAS cycle

1230:    Level: beginner

1232: .seealso: [](ch_snes), `SNESFAS`, `PCMGSetType()`, `PCMGType`
1233: E*/
1234: typedef enum {
1235:   SNES_FAS_MULTIPLICATIVE,
1236:   SNES_FAS_ADDITIVE,
1237:   SNES_FAS_FULL,
1238:   SNES_FAS_KASKADE
1239: } SNESFASType;
1240: PETSC_EXTERN const char *const SNESFASTypes[];

1242: /* called on the finest level FAS instance*/
1243: PETSC_EXTERN PetscErrorCode SNESFASSetType(SNES, SNESFASType);
1244: PETSC_EXTERN PetscErrorCode SNESFASGetType(SNES, SNESFASType *);
1245: PETSC_EXTERN PetscErrorCode SNESFASSetLevels(SNES, PetscInt, MPI_Comm *);
1246: PETSC_EXTERN PetscErrorCode SNESFASGetLevels(SNES, PetscInt *);
1247: PETSC_EXTERN PetscErrorCode SNESFASGetCycleSNES(SNES, PetscInt, SNES *);
1248: PETSC_EXTERN PetscErrorCode SNESFASSetNumberSmoothUp(SNES, PetscInt);
1249: PETSC_EXTERN PetscErrorCode SNESFASSetNumberSmoothDown(SNES, PetscInt);
1250: PETSC_EXTERN PetscErrorCode SNESFASSetCycles(SNES, PetscInt);
1251: PETSC_EXTERN PetscErrorCode SNESFASSetMonitor(SNES, PetscViewerAndFormat *, PetscBool);
1252: PETSC_EXTERN PetscErrorCode SNESFASSetLog(SNES, PetscBool);

1254: PETSC_EXTERN PetscErrorCode SNESFASSetGalerkin(SNES, PetscBool);
1255: PETSC_EXTERN PetscErrorCode SNESFASGetGalerkin(SNES, PetscBool *);
1256: PETSC_EXTERN PetscErrorCode SNESFASGalerkinFunctionDefault(SNES, Vec, Vec, void *);

1258: /* called on any level -- "Cycle" FAS instance */
1259: PETSC_EXTERN PetscErrorCode SNESFASCycleGetSmoother(SNES, SNES *);
1260: PETSC_EXTERN PetscErrorCode SNESFASCycleGetSmootherUp(SNES, SNES *);
1261: PETSC_EXTERN PetscErrorCode SNESFASCycleGetSmootherDown(SNES, SNES *);
1262: PETSC_EXTERN PetscErrorCode SNESFASCycleGetCorrection(SNES, SNES *);
1263: PETSC_EXTERN PetscErrorCode SNESFASCycleGetInterpolation(SNES, Mat *);
1264: PETSC_EXTERN PetscErrorCode SNESFASCycleGetRestriction(SNES, Mat *);
1265: PETSC_EXTERN PetscErrorCode SNESFASCycleGetInjection(SNES, Mat *);
1266: PETSC_EXTERN PetscErrorCode SNESFASCycleGetRScale(SNES, Vec *);
1267: PETSC_EXTERN PetscErrorCode SNESFASCycleSetCycles(SNES, PetscInt);
1268: PETSC_EXTERN PetscErrorCode SNESFASCycleIsFine(SNES, PetscBool *);

1270: /* called on the (outer) finest level FAS to set/get parameters on any level instance */
1271: PETSC_EXTERN PetscErrorCode SNESFASSetInterpolation(SNES, PetscInt, Mat);
1272: PETSC_EXTERN PetscErrorCode SNESFASGetInterpolation(SNES, PetscInt, Mat *);
1273: PETSC_EXTERN PetscErrorCode SNESFASSetRestriction(SNES, PetscInt, Mat);
1274: PETSC_EXTERN PetscErrorCode SNESFASGetRestriction(SNES, PetscInt, Mat *);
1275: PETSC_EXTERN PetscErrorCode SNESFASSetInjection(SNES, PetscInt, Mat);
1276: PETSC_EXTERN PetscErrorCode SNESFASGetInjection(SNES, PetscInt, Mat *);
1277: PETSC_EXTERN PetscErrorCode SNESFASSetRScale(SNES, PetscInt, Vec);
1278: PETSC_EXTERN PetscErrorCode SNESFASGetRScale(SNES, PetscInt, Vec *);
1279: PETSC_EXTERN PetscErrorCode SNESFASSetContinuation(SNES, PetscBool);

1281: PETSC_EXTERN PetscErrorCode SNESFASGetSmoother(SNES, PetscInt, SNES *);
1282: PETSC_EXTERN PetscErrorCode SNESFASGetSmootherUp(SNES, PetscInt, SNES *);
1283: PETSC_EXTERN PetscErrorCode SNESFASGetSmootherDown(SNES, PetscInt, SNES *);
1284: PETSC_EXTERN PetscErrorCode SNESFASGetCoarseSolve(SNES, SNES *);

1286: /* parameters for full FAS */
1287: PETSC_EXTERN PetscErrorCode SNESFASFullSetDownSweep(SNES, PetscBool);
1288: PETSC_EXTERN PetscErrorCode SNESFASCreateCoarseVec(SNES, Vec *);
1289: PETSC_EXTERN PetscErrorCode SNESFASRestrict(SNES, Vec, Vec);
1290: PETSC_EXTERN PetscErrorCode SNESFASFullSetTotal(SNES, PetscBool);
1291: PETSC_EXTERN PetscErrorCode SNESFASFullGetTotal(SNES, PetscBool *);

1293: PETSC_EXTERN PetscErrorCode DMSNESCheckDiscretization(SNES, DM, PetscReal, Vec, PetscReal, PetscReal[]);
1294: PETSC_EXTERN PetscErrorCode DMSNESCheckResidual(SNES, DM, Vec, PetscReal, PetscReal *);
1295: PETSC_EXTERN PetscErrorCode DMSNESCheckJacobian(SNES, DM, Vec, PetscReal, PetscBool *, PetscReal *);
1296: PETSC_EXTERN PetscErrorCode DMSNESCheckFromOptions(SNES, Vec);
1297: PETSC_EXTERN PetscErrorCode DMSNESComputeJacobianAction(DM, Vec, Vec, Vec, void *);
1298: PETSC_EXTERN PetscErrorCode DMSNESCreateJacobianMF(DM, Vec, void *, Mat *);

1300: PETSC_EXTERN PetscErrorCode SNESNewtonALSetFunction(SNES, SNESFunctionFn *, void *ctx);
1301: PETSC_EXTERN PetscErrorCode SNESNewtonALGetFunction(SNES, SNESFunctionFn **, void **ctx);
1302: PETSC_EXTERN PetscErrorCode SNESNewtonALComputeFunction(SNES, Vec, Vec);
1303: PETSC_EXTERN PetscErrorCode SNESNewtonALGetLoadParameter(SNES, PetscReal *);

1305: /*MC
1306:    SNESNewtonALCorrectionType - the approach used by `SNESNEWTONAL` to determine
1307:    the correction to the current increment. While the exact correction satisfies
1308:    the constraint surface at every iteration, it also requires solving a quadratic
1309:    equation which may not have real roots. Conversely, the normal correction is more
1310:    efficient and always yields a real correction and is the default.

1312:    Values:
1313: +   `SNES_NEWTONAL_CORRECTION_EXACT` - choose the correction which exactly satisfies the constraint
1314: -   `SNES_NEWTONAL_CORRECTION_NORMAL` - choose the correction in the updated normal hyper-surface to the constraint surface

1316:    Options Database Key:
1317: . -snes_newtonal_correction_type <exact> - select type from <exact,normal>

1319:    Level: intermediate

1321: .seealso: `SNES`, `SNESNEWTONAL`, `SNESNewtonALSetCorrectionType()`
1322: M*/
1323: typedef enum {
1324:   SNES_NEWTONAL_CORRECTION_EXACT  = 0,
1325:   SNES_NEWTONAL_CORRECTION_NORMAL = 1,
1326: } SNESNewtonALCorrectionType;
1327: PETSC_EXTERN const char *const SNESNewtonALCorrectionTypes[];

1329: PETSC_EXTERN PetscErrorCode SNESNewtonALSetCorrectionType(SNES, SNESNewtonALCorrectionType);