nutopy.path.Options

class Options(*args, **kwargs)[source]

Bases: nutopy.options.Options

Options for nutopy.path.solve.

Variables

  • DispIter (int, default is 1) – Display at iteration k such that mod(k,DispIter)==0

  • Display (str, {‘on’, ‘off’}, default is on) – Display iterations and results or not

  • DoSavePath (str, {‘off’, ‘on’}, default is off) – Save path during the homotopy in a file “SavedPath(n).py”

  • MaxIterCorrection (int, default is 7) – Maximum number of iterations during correction

  • MaxArcLength (float, default is 1e5) – Maximum arc length

  • MaxFunNorm (float, default is 1e-1) – Maximal norm of the function F during homotopy

  • MaxSteps (int, default is 10000) – Maximum number of homotopy steps

  • MaxStepSize (float, default is 0) – Maximum step size during homotopy. If it is equal to 0 then the integrator has no constraint on the maximal step size.

  • MaxStepSizeHomPar (float, default is 0) – Maximum step size for the homotopic parameter. If 0 then no constraint on the maximal step size.

  • ODESolver (str, default is dopri5) –

    Integrator name for homotopy. See Refs. 1 and 2. The integrators are interface of Fortran softwares available here.

    • Explicit:

      dopri5, dop853

    • Implicit:

      radau5, radau9, radau13, radau (adaptative order 5, 9 and 13)

  • StopAtTurningPoint (int, {0, 1}, default is 0) – Stop or not after a turning point.

  • TolOdeAbs (float, default is 1e-10) – Absolute error tolerance.

  • TolOdeRel (float, default is 1e-8) – Relative error tolerance.

  • TolHomparfinalStep (float, default is 1e-8) – Absolute Dense output tolerance. Absolute tolerance to detect if the final homotopic parameter has been reached.

  • TolHomParEvolution (float, default is 1e-8) – Relative Dense output tolerance. The homotopy stops when the homotopic parameter do not evolve relatively, iteration per iteration, during ten following steps.

  • TolXCorrectionStep (float, default is 1e-8) – Relative tolerance during correction.

Examples

>>> from nutopy import path

Constructor usage

>>> options = path.Options()

>>> options = path.Options(Display='off', MaxSf=100)

>>> options = path.Options({'Display' : 'off', 'MaxSf' : 100})

Update

>>> options.update(Display='on')

Get

>>> solver = options.get('Display')

References

1

E. Hairer, S. P. Norsett & G. Wanner, Solving Ordinary Differential Equations I, Nonstiff Problems, vol 8 of Springer Serie in Computational Mathematics, Springer-Verlag, second edn (1993).

2

E. Hairer & G. Wanner, Solving Ordinary Differential Equations II, Stiff and Differential-Algebraic Problems, vol 14 of Springer Serie in Computational Mathematics, Springer-Verlag, second edn (1996).

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