model.ACBasic module¶
Author: | Dominic Hunt |
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Reference: | Based on ideas we had. |
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class
model.ACBasic.
ACBasic
(alpha=0.3, beta=4, invBeta=None, alphaE=None, alphaA=None, expect=None, actorExpect=None, **kwargs)[source]¶ Bases:
model.modelTemplate.Model
A basic, complete actor-critic model
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Name
¶ The name of the class used when recording what has been used.
Type: string
Parameters: - alpha (float, optional) – Learning rate parameter
- alphaE (float, optional) – Learning rate parameter for the update of the expectations. Default
lpha
- alphaA (float, optional) – Learning rate parameter for the update of the actor. Default
lpha
- beta (float, optional) – Sensitivity parameter for probabilities
- invBeta (float, optional) – Inverse of sensitivity parameter.
Defined as \(\frac{1}{\beta+1}\). Default
0.2
- number_actions (integer, optional) – The maximum number of valid actions the model can expect to receive. Default 2.
- number_cues (integer, optional) –
- The initial maximum number of stimuli the model can expect to receive.
- Default 1.
- number_critics (integer, optional) – The number of different reaction learning sets. Default number_actions*number_cues
- action_codes (dict with string or int as keys and int values, optional) – A dictionary used to convert between the action references used by the task or dataset and references used in the models to describe the order in which the action information is stored.
- prior (array of floats in
[0, 1]
, optional) – The prior probability of of the states being the correct one. Defaultones((number_actions, number_cues)) / number_critics)
- expect (array of floats, optional) – The initialisation of the expected reward.
Default
ones((number_actions, number_cues)) * 5 / number_cues
- stimFunc (function, optional) – The function that transforms the stimulus into a form the model can understand and a string to identify it later. Default is blankStim
- rewFunc (function, optional) – The function that transforms the reward into a form the model can understand. Default is blankRew
- decFunc (function, optional) – The function that takes the internal values of the model and turns them in to a decision. Default is model.decision.discrete.weightProb
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actorStimulusProbs
()[source]¶ Calculates in the model-appropriate way the probability of each action.
Returns: probabilities – The probabilities associated with the action choices Return type: 1D ndArray of floats
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calcProbabilities
(actionValues)[source]¶ Calculate the probabilities associated with the actions
Parameters: actionValues (1D ndArray of floats) – Returns: probArray – The probabilities associated with the actionValues Return type: 1D ndArray of floats
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delta
(reward, expectation, action, stimuli)[source]¶ Calculates the comparison between the reward and the expectation
Parameters: Returns: Return type: delta
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returnTaskState
()[source]¶ Returns all the relevant data for this model
Returns: results – The dictionary contains a series of keys including Name, Probabilities, Actions and Events. Return type: dict
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rewardExpectation
(observation)[source]¶ Calculate the estimated reward based on the action and stimuli
This contains parts that are task dependent
Parameters: observation ({int | float | tuple}) – The set of stimuli Returns: - actionExpectations (array of floats) – The expected rewards for each action
- stimuli (list of floats) – The processed observations
- activeStimuli (list of [0, 1] mapping to [False, True]) – A list of the stimuli that were or were not present
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storeState
()[source]¶ Stores the state of all the important variables so that they can be accessed later
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updateModel
(delta, action, stimuli, stimuliFilter)[source]¶ Parameters: - delta (float) – The difference between the reward and the expected reward
- action (int) – The action chosen by the model in this trialstep
- stimuli (list of float) – The weights of the different stimuli in this trialstep
- stimuliFilter (list of bool) – A list describing if a stimulus cue is present in this trialstep
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