scipy.signal.

step#

scipy.signal.step(system, X0=None, T=None, N=None)[source]#

Step response of continuous-time system.

Parameters:

systeman instance of the LTI class or a tuple of array_like

describing the system. The following gives the number of elements in the tuple and the interpretation:

1 (instance of lti)

2 (num, den)

3 (zeros, poles, gain)

4 (A, B, C, D)

X0array_like, optional

Initial state-vector (default is zero).

Tarray_like, optional

Time points (computed if not given).

Nint, optional

Number of time points to compute if T is not given.

Returns:

T1D ndarray: Output time points.
yout1D ndarray: Step response of system.

Notes

If (num, den) 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]).

Array API Standard Support

step 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 Support for the array API standard for more information.

Examples

>>> from scipy import signal
>>> import matplotlib.pyplot as plt
>>> lti = signal.lti([1.0], [1.0, 1.0])
>>> t, y = signal.step(lti)
>>> plt.plot(t, y)
>>> plt.xlabel('Time [s]')
>>> plt.ylabel('Amplitude')
>>> plt.title('Step response for 1. Order Lowpass')
>>> plt.grid()