scipy.signal.lti

class scipy.signal.lti(*system)

Linear Time Invariant system base class.

Parameters:

*system : arguments

The lti class can be instantiated with either 2, 3 or 4 arguments. The following gives the number of arguments and the corresponding subclass that is created:

• 2: TransferFunction: (numerator, denominator)
• 3: ZerosPolesGain: (zeros, poles, gain)
• 4: StateSpace: (A, B, C, D)

Each argument can be an array or a sequence.

Notes

lti instances do not exist directly. Instead, lti creates an instance of one of its subclasses: StateSpace, TransferFunction or ZerosPolesGain.

Changing the value of properties that are not directly part of the current system representation (such as the zeros of a StateSpace system) is very inefficient and may lead to numerical inaccuracies.

Attributes

A	State matrix of the StateSpace system.
B	Input matrix of the StateSpace system.
C	Output matrix of the StateSpace system.
D	Feedthrough matrix of the StateSpace system.
den	Denominator of the TransferFunction system.
gain	Gain of the ZerosPolesGain system.
num	Numerator of the TransferFunction system.
poles	Poles of the ZerosPolesGain system.
zeros	Zeros of the ZerosPolesGain system.

Methods

bode([w, n])	Calculate Bode magnitude and phase data of a continuous-time system.
freqresp([w, n])	Calculate the frequency response of a continuous-time system.
impulse([X0, T, N])	Return the impulse response of a continuous-time system.
output(U, T[, X0])	Return the response of a continuous-time system to input U.
step([X0, T, N])	Return the step response of a continuous-time system.