cupyx.scipy.signal.square#

cupyx.scipy.signal.square(t, duty=0.5)[source]#

Return a periodic square-wave waveform.

The square wave has a period 2*pi, has value +1 from 0 to 2*pi*duty and -1 from 2*pi*duty to 2*pi. duty must be in the interval [0,1].

Note that this is not band-limited. It produces an infinite number of harmonics, which are aliased back and forth across the frequency spectrum.

Parameters:

  • t (array_like) – The input time array.

  • duty (array_like, optional) – Duty cycle. Default is 0.5 (50% duty cycle). If an array, causes wave shape to change over time, and must be the same length as t.

Returns:

y – Output array containing the square waveform.

Return type:

ndarray

Examples

A 5 Hz waveform sampled at 500 Hz for 1 second:

>>> import cupyx.scipy.signal
>>> import cupy as cp
>>> import matplotlib.pyplot as plt
>>> t = cupy.linspace(0, 1, 500, endpoint=False)
>>> plt.plot(cupy.asnumpy(t), cupy.asnumpy(cupyx.scipy.signal.square(2 * cupy.pi * 5 * t)))
>>> plt.ylim(-2, 2)

A pulse-width modulated sine wave:

>>> plt.figure()
>>> sig = cupy.sin(2 * cupy.pi * t)
>>> pwm = cupyx.scipy.signal.square(2 * cupy.pi * 30 * t, duty=(sig + 1)/2)
>>> plt.subplot(2, 1, 1)
>>> plt.plot(cupy.asnumpy(t), cupy.asnumpy(sig))
>>> plt.subplot(2, 1, 2)
>>> plt.plot(cupy.asnumpy(t), cupy.asnumpy(pwm))
>>> plt.ylim(-1.5, 1.5)