PETScSNESSolver.h

Note

The documentation on this page was automatically extracted from the DOLFIN C++ code and may need to be edited or expanded.

class PETScSNESSolver

Parent class(es)

• PETScObject

This class implements methods for solving nonlinear systems via PETSc’s SNES interface. It includes line search and trust region techniques for globalising the convergence of the nonlinear iteration.

PETScSNESSolver(std::string nls_type = "default")

Create SNES solver for a particular method

std::pair<std::size_t, bool> solve(NonlinearProblem &nonlinear_problem, GenericVector &x, const GenericVector &lb, const GenericVector &ub)

Solve a nonlinear variational inequality with bound constraints

Arguments

nonlinear_function (NonlinearProblem)

The nonlinear problem.

x (GenericVector)

The vector.

lb (GenericVector)

The lower bound.

ub (GenericVector)

The upper bound.

Returns

std::pair<std::size_t, bool>

Pair of number of Newton iterations, and whether iteration converged)

std::pair<std::size_t, bool> solve(NonlinearProblem &nonlinear_function, GenericVector &x)

Solve abstract nonlinear problem \(F(x) = 0\) for given \(F\) and Jacobian \(\dfrac{\partial F}{\partial x}\).

Arguments

nonlinear_function (NonlinearProblem)

The nonlinear problem.

x (GenericVector)

The vector.

Returns

std::pair<std::size_t, bool>

Pair of number of Newton iterations, and whether iteration converged)

static std::vector<std::pair<std::string, std::string>> methods()

Return a list of available solver methods

static Parameters default_parameters()

Default parameter values

boost::shared_ptr<SNES> snes() const

Return PETSc SNES pointer

void init(const std::string &method)

Initialize SNES solver

void set_linear_solver_parameters()

Update the linear solver parameters

static PetscErrorCode FormFunction(SNES snes, Vec x, Vec f, void *ctx)

The callback for PETSc to compute F, the nonlinear residual

static PetscErrorCode FormJacobian(SNES snes, Vec x, Mat *A, Mat *B, MatStructure *flag, void *ctx)

The callback for PETSc to compute A, the Jacobian

void set_bounds(GenericVector &x)

Set the bounds on the problem from the parameters, if desired Here, x is passed in as a model vector from which we make our Vecs that tell PETSc the bounds if the “sign” parameter is used.