nace 0.0.8

A re-implementation of NACE, as a pypi package, with a cleaner more general interface.

An Observational learner, creating a model of the world from subsequent observations, which resolves
conflicting information, and can plan many steps ahead.

Background

This project builds upon an implementation of Patrick Hammer's NACE work observational learner , which in turn was based on Berick Cook's AIRIS, with support for partial observability. The aim is to enhance its capabilities to handle non-deterministic and non-stationary environments, as well as changes external to the agent. This will initially be achieved by incorporating relevant components of Non-Axiomatic Logic (NAL).

Examples

Data Structures

 
  = Rule Object =:
  Action_Value_Precondition:                                            Prediction:    State Value Deltas
  Action   State   Preconditions (old world)                            y  x  board    score     key
           values  precondition0    precondition1    precondition2            value    delta     delta 
           excl    y  x             y  x
           score
  ((left,  (0,),  (0, 0, ' '),     (0, 1, 'x'),     (0, 2, 'u')),      (0, 0, 'x',     (0,       0))),
  ((right, (0,),  (0, -1, 'x'),    (0, 0, 'o')),                       (0, 0, 'o',     (0,       0))),
  
  The following Action_Value_Precondition:
  ((right, (0,),  (0, -1, 'x'),    (0, 0, 'o'))
  can be read: Match if there is a 'o' at the focus point, and a 'x' to the left of it, and the action is right.
  
  The following Action_Value_Precondition, Prediction:
  ((left,  (0,),  (0, 0, ' '),     (0, 1, 'x'),     (0, 2, 'u')),      (0, 0, 'x',     (0,       0))),
  can be read: Match if there is a ' ' at the focus point, 
                        and a 'x' to the right of it, 
                        and a 'u' to the right of the 'x',
                        and the action is left
                And the prediction after the action is:
                        the 'x' will appear at 0,0 relative to the focus point.
                        and there is no change to our score

  The following Action_Value_Precondition, Prediction:
  ((right, (0,), (0, -1, 'x'), (0, 0, 'f')), (0, 0, 'x', (1, 0))),
  can be read: Match if there is a 'f' at the focus point, 
                        and a 'x' to the left of it, 
                        and the action is right
                And the prediction after the action is:
                        the 'x' will appear at 0,0 relative to the focus point.
                        the first State Delta (score) will be +1
                        the first State Delta (key) will be +0
  
  
  Rule_Evidence Object Dictionary
                                 positive       negative
                                 evidence       evidence
                                 counter        counter
  { ((right, ... ))       :    ( 1,             0                ) }
  
 { ((left, (), (0, 0, ' '), (0, 1, 'x')), (0, 0, 'x', (0,))): (1,0) }    
  
  Positive Evidence, and Negative Evidence can be used to calculate:
        Frequency         = positive_count / (positive_count + negative_count)
        Confidence        = (positive_count + negative_count) / (positive_count + negative_count + 1)
        Truth_expectation = confidence * (frequency - 0.5) + 0.5

  Location:  
    xy_loc tuple (x,y) not (0,0) is top left
  
  
  State Values