PETScSNESSolver

class dolfin.cpp.la.PETScSNESSolver(*args)

Bases: dolfin.cpp.la.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.

Overloaded versions

• PETScSNESSolver(comm)

  Create SNES solver

• PETScSNESSolver(nls_type=”default”)

  Create SNES solver for a particular method

static default_parameters()

Default parameter values

get_options_prefix()

Returns the prefix used by PETSc when searching the PETSc options database

init()

Set up the SNES object, but don’t do anything yet, in case the user wants to access the SNES object directly

static methods()

Return a list of available solver methods

mpi_comm()

Return the MPI communicator

parameters

set_from_options()

Set options from the PETSc options database

set_options_prefix()

Sets the prefix used by PETSc when searching the PETSc options database

snes()

Return petsc4py representation of PETSc SNES solver

solve()

Overloaded versions

• solve(nonlinear_problem, x, lb, 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

  (int, bool)

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

• solve(nonlinear_function, 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

  (int, bool)

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

thisown

The membership flag