periodic-function

Collection of periodic functions with period normalized to turns.

Usage

const fn = require('periodic-function/<fn>')

//π radians
let halfTurn = fn(.5)

//2π radians
let fullTurn = fn(1)

API

let fn = require('periodic-function/<fn>')

The fn takes the amount of turn t as the first argument and optional parameters. The list of available functions:

Signature	Waveform	Meaning
sine(t, phase=0)		Math.sin normalized to 0..1 rather than radians 0..2π. To turn into cos, set phase=.25.
triangle(t, ratio=0.5)		Triangular waveform with regulated ratio. To turn into sawtooth set ratio=0 or ratio=1.
sawtooth(t, inverse=false)		Edge case of triangular waveform, whether descending or ascending.
square(t, ratio=0.5)		Rectangular waveform with regulated ratio. To turn into pulse set ratio=0.
pulse(t, tlr=0)		Delta-pulse, which is 1 at 0 and 0 anywhere else. Pass tlr as a precision tolerance, ie. 1e-5.
fourier(t, real, imag?, normalize=false)		Fourier Series coefficients, ie. harmonics. 0 harmonic is static level, 1st is base frequency, 2nd is double base frequency, 3rd is triple etc. Set normalize=true to bring max harmonic to 1.
clausen(t, limit=10)		Clausen function. Pass limit to indicate number of iterations, precision/performance tradeoff.
step(t, samples)		Step function, picks closest sample value out of a set.
interpolate(t, samples)		Interpolates between closest values in a sample set.
noise(t)		Repeated sample of noise.

If you feel like it is not complete list of you know example of a good periodic function, suitable for dsp, welcome to contribute.

Related

• audio-oscillator
• createPeriodicWave
• List of periodic functions

Credits

© 2017 Dima Yv. MIT License