egttools.games.abstract_games.AbstractNPlayerGameExpectedPayoff

class AbstractNPlayerGameExpectedPayoff(self: egttools.numerical.numerical.games.AbstractNPlayerGame, nb_strategies: int, group_size: int)[source]

Bases: AbstractNPlayerGame

This abstract Game class can be used in most scenarios where the fitness of a strategy is calculated as its expected payoff given the population state.

It assumes that the game is N player, since the fitness of a strategy given a population state is calculated as the expected payoff of that strategy over all possible group combinations in the given state.

Notes

It might be a good idea to overwrite the methods __str__, type, and save_payoffs to adapt to your given game implementation

It assumes that you have at least the following attributes:

1. And an attribute self.nb_strategies_ which contains the number of strategies that you are going to analyse for the given game. 2. self.payoffs() returns a numpy.ndarray and contain the payoff matrix of the game. This array is of shape (self.nb_strategies(), self.nb_group_configurations()), where self.nb_group_configurations() is the number of possible combinations of strategies in the group. Thus, each row should give the (expected) payoff of the row strategy when playing in a group with the column configuration. The payoff method provides an easy way to access the payoffs for any group composition, by taking as arguments the index of the row strategy and a List with the count of each possible strategy in the group.

You must still implement the methods play which should define how the game assigns payoffs to each strategy for a given game context. In particular, calculate_payoffs should fill the array self.payoffs_ with the correct values as explained above. We recommend that you run this method in the __init__ (initialization of the object) since, these values must be set before passing the game object to the numerical simulator (e.g., egttools.numerical.PairwiseComparisonNumerical).

Abstract N-Player Game.

This abstract Game class can be used in most scenarios where the fitness of a strategy is calculated as its expected payoff given the population state.

It assumes that the game is N player, since the fitness of a strategy given a population state is calculated as the expected payoff of that strategy over all possible group combinations in the given state.

Notes

It might be a good idea to overwrite the methods __str__, type, and save_payoffs to adapt to your given game implementation

It assumes that you have at least the following attributes: 1. And an attribute self.nb_strategies_ which contains the number of strategies that you are going to analyse for the given game. 2. self.payoffs_ which must be a numpy.ndarray and contain the payoff matrix of the game. This array must be of shape (self.nb_strategies_, nb_group_configurations), where nb_group_configurations is the number of possible combinations of strategies in the group. Thus, each row should give the (expected) payoff of the row strategy when playing in a group with the column configuration. The payoff method provides an easy way to access the payoffs for any group composition, by taking as arguments the index of the row strategy and a List with the count of each possible strategy in the group.

You must still implement the methods play and calculate_payoffs which should define how the game assigns payoffs to each strategy for each possible game context. In particular, calculate_payoffs should fill the array self.payoffs_ with the correct values as explained above. We recommend that you run this method in the __init__ (initialization of the object) since, these values must be set before passing the game object to the numerical simulator (e.g., egttools.numerical.PairwiseComparisonNumerical).

Parameters
  • nb_strategies (int) – total number of possible strategies.

  • group_size (int) – size of the group in which the game will take place.

Methods

calculate_fitness

Estimates the fitness for a player_type in the population with state :param strategies.

calculate_payoffs

This method calculates the payoffs for each strategy in each possible group configuration.

group_size

Size of the group.

nb_group_configurations

Number of different group configurations.

nb_strategies

Number of different strategies playing the game.

payoff

Returns the payoff of a strategy given a group composition.

payoffs

Returns the payoff matrix of the game.

play

This method fills the game_payoffs container with the payoff of each strategy given the group_composition.

save_payoffs

Stores the payoff matrix in a txt file.

type

returns the type of game.

update_payoff

update an entry of the payoff matrix

__init__(self: egttools.numerical.numerical.games.AbstractNPlayerGame, nb_strategies: int, group_size: int) None

Abstract N-Player Game.

This abstract Game class can be used in most scenarios where the fitness of a strategy is calculated as its expected payoff given the population state.

It assumes that the game is N player, since the fitness of a strategy given a population state is calculated as the expected payoff of that strategy over all possible group combinations in the given state.

Notes

It might be a good idea to overwrite the methods __str__, type, and save_payoffs to adapt to your given game implementation

It assumes that you have at least the following attributes: 1. And an attribute self.nb_strategies_ which contains the number of strategies that you are going to analyse for the given game. 2. self.payoffs_ which must be a numpy.ndarray and contain the payoff matrix of the game. This array must be of shape (self.nb_strategies_, nb_group_configurations), where nb_group_configurations is the number of possible combinations of strategies in the group. Thus, each row should give the (expected) payoff of the row strategy when playing in a group with the column configuration. The payoff method provides an easy way to access the payoffs for any group composition, by taking as arguments the index of the row strategy and a List with the count of each possible strategy in the group.

You must still implement the methods play and calculate_payoffs which should define how the game assigns payoffs to each strategy for each possible game context. In particular, calculate_payoffs should fill the array self.payoffs_ with the correct values as explained above. We recommend that you run this method in the __init__ (initialization of the object) since, these values must be set before passing the game object to the numerical simulator (e.g., egttools.numerical.PairwiseComparisonNumerical).

Parameters
  • nb_strategies (int) – total number of possible strategies.

  • group_size (int) – size of the group in which the game will take place.

__new__(**kwargs)
__str__(self: egttools.numerical.numerical.games.AbstractNPlayerGame) str
calculate_fitness(self: egttools.numerical.numerical.games.AbstractNPlayerGame, strategy_index: int, pop_size: int, strategies: numpy.ndarray[numpy.uint64[m, 1]]) float

Estimates the fitness for a player_type in the population with state :param strategies.

This function assumes that the player with strategy player_type is not included in the vector of strategy counts strategies.

Parameters
  • strategy_index (int) – The index of the strategy used by the player.

  • pop_size (int) – The size of the population.

  • strategies (numpy.ndarray[numpy.uint64[m, 1]]) – A vector of counts of each strategy. The current state of the population.

Returns

The fitness of the strategy in the population state given by strategies.

Return type

float

calculate_payoffs()[source]

This method calculates the payoffs for each strategy in each possible group configuration. Thus, it must fill the self.payoffs_ numpy.ndarray with these payoffs values. This array must be of shape (self.nb_strategies_, nb_group_configurations), where nb_group_configurations is the number of possible combinations of strategies in the group. Thus, each row should give the (expected) payoff of the row strategy when playing in a group with the column configuration.

Returns

The payoff matrix of the game.

Return type

numpy.ndarray

group_size(self: egttools.numerical.numerical.games.AbstractNPlayerGame) int

Size of the group.

nb_group_configurations(self: egttools.numerical.numerical.games.AbstractNPlayerGame) int

Number of different group configurations.

nb_strategies(self: egttools.numerical.numerical.games.AbstractNPlayerGame) int

Number of different strategies playing the game.

payoff(self: egttools.numerical.numerical.games.AbstractNPlayerGame, strategy: int, group_composition: List[int]) float

Returns the payoff of a strategy given a group composition.

If the group composition does not include the strategy, the payoff should be zero.

Parameters
  • strategy (int) – The index of the strategy used by the player.

  • group_composition (List[int]) – List with the group composition. The structure of this list depends on the particular implementation of this abstract method.

Returns

The payoff value.

Return type

float

payoffs(self: egttools.numerical.numerical.games.AbstractNPlayerGame) numpy.ndarray[numpy.float64[m, n]]

Returns the payoff matrix of the game.

Returns

The payoff matrix.

Return type

numpy.ndarray

abstract play(group_composition, game_payoffs)[source]

This method fills the game_payoffs container with the payoff of each strategy given the group_composition.

Strategies not present in the group will receive 0 payoff by default.

Parameters
  • group_composition (Union[List[int], numpy.ndarray]) – A List or a numpy.ndarray containing the counts of each strategy in the group (e.g., for a game with 3 possible strategies and group size 4, the following List is possible [3, 0, 1]).

  • game_payoffs (numpy.ndarray) – A container for the payoffs that will be calculated. This avoids needing to create a new array at each call and should speed up computation.

Return type

None

save_payoffs(self: egttools.numerical.numerical.games.AbstractNPlayerGame, file_name: str) None

Stores the payoff matrix in a txt file.

Parameters

file_name (str) – Name of the file in which the data will be stored.

type(self: egttools.numerical.numerical.games.AbstractNPlayerGame) str

returns the type of game.

update_payoff(self: egttools.numerical.numerical.games.AbstractNPlayerGame, strategy_index: int, group_configuration_index: int, value: float) None

update an entry of the payoff matrix