pygambit.nash.ipa_solve#

pygambit.nash.ipa_solve(perturbation: Game | MixedStrategyProfile, nash_callback: Callable[[MixedStrategyProfileDouble], None] | None = None, event_callback: Callable[[IPAStepEvent | IPATerminationEvent], None] | None = None) → IPAResult#

Compute a Nash equilibrium of a game using iterated polymatrix approximation.

Parameters:

  • perturbation (Game or MixedStrategyProfile) –

    The perturbation vector to apply to the game. If a Game is passed, the perturbation vector is set to be 1 for the first strategy for each player and 0 for all other strategies. If a MixedStrategyProfileRational is given, it is converted to floating-point precision first.

    Changed in version 16.2.0: Allow selection of the perturbation vector

    Changed in version 17.0.0: Accept a MixedStrategyProfileRational, converted to floating-point via ~MixedStrategyProfile.as_float.

  • nash_callback (Callable[[MixedStrategyProfileDouble], None], optional) –

    If specified, called with the equilibrium found, if any.

    Added in version 17.0.0.

  • event_callback (Callable[[IPAStepEvent | IPATerminationEvent], None], optional) –

    If specified, called with the state of the approximating strategy at the end of each iteration (IPAStepEvent) and, possibly more than once, with why an iteration terminated (IPATerminationEvent).

    Added in version 17.0.0.

Raises:

ValueError – If the perturbation vector does not have a unique maximizer for each player

Returns:

res – The result represented as an IPAResult object.

Return type:

IPAResult