xref: /petsc/src/snes/impls/al/alimpl.h (revision 447e0e2062395afab88d46916d90376f9cc66fab)
1 /*
2    Private context for a Newton arc length continuation
3    method for solving systems of nonlinear equations
4 */
5 
6 #pragma once
7 #include <petsc/private/snesimpl.h>
8 #include <petscsnes.h>
9 
10 typedef struct {
11   PetscInt                   max_continuation_steps; /* maximum number of continuation steps */
12   PetscReal                  step_size;              /* radius of quadratic constraint surface */
13   PetscReal                  psisq;                  /* load factor regularization parameter */
14   PetscReal                  lambda_update;          /* accumulated update to lambda over the current increment */
15   PetscReal                  lambda;                 /* load parameter */
16   PetscReal                  lambda_max;             /* maximum value of the load parameter */
17   PetscReal                  lambda_min;             /* minimum value of the load parameter */
18   PetscBool                  scale_rhs;              /* should the RHS vector be scaled by the load parameter? */
19   SNESNewtonALCorrectionType correction_type;        /* type of correction scheme to use */
20   PetscBool                  copied_rhs;             /* has the right-hand side vector been copied? */
21 
22   Vec vec_rhs_orig; /* original right-hand side vector, used if `scale_rhs == PETSC_TRUE` */
23 
24   SNESFunctionFn *computealfunction; /* user-provided function to compute the tangent load vector  */
25   void           *alctx;             /* user-provided context for the tangent load vector computation */
26 } SNES_NEWTONAL;
27 
28 PETSC_INTERN const char NewtonALExactCitation[];
29 PETSC_INTERN PetscBool  NewtonALExactCitationSet;
30 PETSC_INTERN const char NewtonALNormalCitation[];
31 PETSC_INTERN PetscBool  NewtonALNormalCitationSet;
32