`scipy.signal._ltisys:lti`

source: /scipy/signal/_ltisys.py :136

Signature

class lti ( * system )

Members

Summary

Continuous-time 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 continuous-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.

Notes

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

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

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.

Array API Standard Support

lti 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.lti(1, 2, 3, 4)

✓

Construct the transfer function :math:`H(s) = \frac{5(s - 1)(s - 2)}{(s - 3)(s - 4)}`:

signal.lti([1, 2], [3, 4], 5)

✓

Construct the transfer function :math:`H(s) = \frac{3s + 4}{1s + 2}`:

signal.lti([3, 4], [1, 2])

`scipy.signal._ltisys:lti`

Signature

Members

Summary

Parameters

Notes

Examples

See also

Aliases

Referenced by

This package