# scipy.signal.dstep

scipy.signal.dstep(system, x0=None, t=None, n=None)

  Step response of discrete-time system.

  Parameters:
    system tuple of array_like

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

      > - 1: (instance of `dlti`)

      > - 3: (num, den, dt)

      > - 4: (zeros, poles, gain, dt)

      > - 5: (A, B, C, D, dt)

    x0 array_like, optional

      Initial state-vector. Defaults to zero.

    t array_like, optional

      Time points. Computed if not given.

    n int, optional

      The number of time points to compute (if t is not given).

  Returns:
    tout ndarray

      Output time points, as a 1-D array.

    yout tuple of ndarray

      Step response of system. Each element of the tuple represents the output of the system based on a step response to each input.

  See also

  `step`, `dimpulse`, `dlsim`, `cont2discrete`

  Examples

      >>> import numpy as np
      >>> from scipy import signal
      >>> import matplotlib.pyplot as plt

      >>> butter = signal.dlti(*signal.butter(3, 0.5))
      >>> t, y = signal.dstep(butter, n=25)
      >>> plt.step(t, np.squeeze(y))
      >>> plt.grid()
      >>> plt.xlabel('n [samples]')
      >>> plt.ylabel('Amplitude')