Module ltism :: Class LTISM
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Class LTISM

sm.SM --+
        |
       LTISM

Class of state machines describable as LTI systems

Instance Methods
 
__init__(self, dCoeffs, cCoeffs, previousInputs=None, previousOutputs=None)
Expects coefficients in the form y[n] = c_0 y[n-1] + c_(k-1) y[n-k] + d_0 x[n] + d_1 x[n-1] + ... + d_j x[n-j] Coefficients for newest state and input are at the front
 
getNextValues(self, state, input)
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
  cCoeffs
Output coefficients
  dCoeffs
Input coefficients
  startState
State is last j input values and last k output values
Method Details

__init__(self, dCoeffs, cCoeffs, previousInputs=None, previousOutputs=None)
(Constructor)

 

Expects coefficients in the form y[n] = c_0 y[n-1] + c_(k-1) y[n-k] + d_0 x[n] + d_1 x[n-1] + ... + d_j x[n-j] Coefficients for newest state and input are at the front

Parameters:
  • previousInputs - list of historical inputs running from x[-1] (at the beginning of the list) to x[-j] at the end of the list, where j is len(self.dCoeffs)-1. If omitted, will default to a list of the appropriate number of zeroes, corresponding to the system being 'at rest'.
  • previousOutputs - list of historical outputs running from y[-1] (at the beginning of the list) to y[-k] (at the end of the list), where k is len(self.cCoeffs). If omitted, will default to a list of the appropriate number of zeroes, corresponding to the system being 'at rest'.
Returns:
A state machine that uses this difference equation to transduce the sequence of inputs X to the sequences of outputs Y, starting from a state determined by previousInputs and previousOutputs

getNextValues(self, state, input)

 

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)