`scipy.signal._ltisys:dlti`

source: /scipy/signal/_ltisys.py :303

Signature

class dlti ( * system , ** kwargs )

Members

Summary

Discrete-time linear time invariant system base class.

Parameters

*system: arguments

The dlti class can be instantiated with either 2, 3 or 4 arguments. The following gives the number of arguments and the corresponding discrete-time 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.

dt: float, optional

Sampling time [s] of the discrete-time systems. Defaults to True (unspecified sampling time). Must be specified as a keyword argument, for example, dt=0.1.

Notes

dlti instances do not exist directly. Instead, dlti 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. It is better to convert to the specific system representation first. For example, call sys = sys.to_zpk() before accessing/changing the zeros, poles or gain.

If (numerator, denominator) is passed in for *system, coefficients for both the numerator and denominator should be specified in descending exponent order (e.g., z^2 + 3z + 5 would be represented as [1, 3, 5]).

Array API Standard Support

dlti has experimental support for Python Array API Standard compatible backends in addition to NumPy. Please consider testing these features by setting an environment variable SCIPY_ARRAY_API=1 and providing CuPy, PyTorch, JAX, or Dask arrays as array arguments. The following combinations of backend and device (or other capability) are supported.

====================  ====================  ====================
Library               CPU                   GPU
====================  ====================  ====================
NumPy                 ✅                     n/a                 
CuPy                  n/a                   ⛔                   
PyTorch               ⛔                     ⛔                   
JAX                   ⛔                     ⛔                   
Dask                  ⛔                     n/a                 
====================  ====================  ====================

See dev-arrayapi for more information.

Examples

from scipy import signal

✓

signal.dlti(1, 2, 3, 4)

✓

signal.dlti(1, 2, 3, 4, dt=0.1)

✓

Construct the transfer function :math:`H(z) = \frac{5(z - 1)(z - 2)}{(z - 3)(z - 4)}` with a sampling time of 0.1 seconds:

signal.dlti([1, 2], [3, 4], 5, dt=0.1)

✓

Construct the transfer function :math:`H(z) = \frac{3z + 4}{1z + 2}` with a sampling time of 0.1 seconds:

signal.dlti([3, 4], [1, 2], dt=0.1)

✓

Aliases

scipy.signal.dlti

Referenced by

This package

release:0.18.0-notes