square

Builtin index · Plotting

result = square(freq, fs, n, [duty=])

Input: freq, fs, n, duty · Output: result

What it is

A bipolar (±1) periodic pulse train. freq (number, Hz) is the repetition rate; fs (number, Hz) is the sample rate the train is generated at; n (number) is how many samples to produce; duty= (number, 0–1, default 0.5) is the fraction of each period spent at +1 rather than -1.

Overloads

One call shape — this function is not overloaded.

Examples

From the documentation, and run by the build -- the output and the figure below are what the engine actually produced. Simplest first.

a = square(100, 1000, 8, duty=0.25)
b = signals.square(100, 1000, 8, duty=0.25)
print("a = {a}")
print("b = {b}")
print("identical = {a == b}")

from tour

a = square(100, 1000, 20, duty=0.25)
b = signals.square(100, 1000, 20, duty=0.25)   # identical to `a`

print("square: {a}")
print("signals.square matches: {max(abs(a - b)) < 1e-12}")

square: signal(Fs=1000) [1, 1, 1, -1, -1, -1, -1, -1, ... (20 elements)]
signals.square matches: true

from signal-processing

s = sine(1 kHz, 48 kHz, 4800)             # a single tone

c = chirp(20, 20000, 48 kHz, 48000)       # linear sweep, 20Hz to 20kHz

lc = chirp(20, 20000, 48 kHz, 48000, method="logarithmic")
sq = square(100, 1000, 1000, duty=0.3)    # bipolar (+-1) pulse train

p = pwm(modulator, 5000, 48000)           # natural-sampling PWM against

                                           # a triangle carrier (duty

                                           # follows the modulator's value)

from numerics-dsp

How it works

square(freq, fs, n, [duty=]) — a bipolar (±1) periodic pulse train ("binary pulses"), duty (default 0.5) the fraction of each period spent at +1.

From the note above this builtin in the interpreter, where the reasoning was written down as it was built.