Module ssm :: Class StochasticSM
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Class StochasticSM

sm.SM --+
        |
       StochasticSM
Known Subclasses:

Stochastic state machine.

Instance Methods
 
__init__(self, startDistribution, transitionDistribution, observationDistribution, beliefDisplayFun=None, sensorDisplayFun=None)
 
startState(self)
 
getNextValues(self, state, inp)
Default version of this method.

Inherited from sm.SM: check, doTraceTasks, done, getStartState, guaranteeName, isDone, printDebugInfo, run, start, step, transduce, transduceF

Class Variables

Inherited from sm.SM: legalInputs, name

Instance Variables
  startDistribution
dist.DDist over states.
  transitionDistribution
A procedure that takes an action and returns a procedure, which takes an old state and returns a distribution over new states.
  observationDistribution
A procedure that takes a state and returns a distribution over observations.
  beliefDisplayFun
(Optional) function that is not used here, but that state estimator, for example, might call to display a belief state.
  sensorDisplayFun
(Optional) function that is not used here, but that state estimator, for example, might call to display a sensor likelihoods.
Method Details

__init__(self, startDistribution, transitionDistribution, observationDistribution, beliefDisplayFun=None, sensorDisplayFun=None)
(Constructor)

 
Parameters:
  • transitionDistribution - P(S_t+1 | S_t, A_t) represented as a procedure that takes an action and returns a procedure. The returned procedure takes an old state and returns a distribution over new states.
  • observationDistribution - P(O_t | S_t) represented as a procedure that takes a state and returns a distribution over observations.
  • startDistribution - distribution on states, represented as a dist.DDist
  • beliefDisplayFun - optional function that is not used here, but that state estimator, for example, might call to display a belief state. Takes a belief state {dist.DDist} as input.
  • sensorDisplayFun - optional function that is not used here, but that state estimator, for example, might call to display a sensor likelihoods. Takes an observation as input.

startState(self)

 
Overrides: startState

getNextValues(self, state, inp)

 

Default version of this method. If a subclass only defines getNextState, then we assume that the output of the machine is the same as its next state.

Overrides: sm.SM.getNextValues
(inherited documentation)

Instance Variable Details

beliefDisplayFun

(Optional) function that is not used here, but that state estimator, for example, might call to display a belief state. Takes a belief state {dist.DDist} as input.

sensorDisplayFun

(Optional) function that is not used here, but that state estimator, for example, might call to display a sensor likelihoods. Takes an observation as input.