This project is part of the @thi.ng/umbrella monorepo.

• About
  • Status
• Installation
• Dependencies
• Usage examples
• API
  • IGen
    • Higher order generators
    • Oscillators
    • LFO
  • Filters
    • 1-pole low pass
    • Frequency modulated osc & 1-pole low pass
    • 1-pole all-pass
    • 2-pole all-pass
  • DelayLine
  • FFT
  • Window functions
• Authors
• License

Composable signal generators, oscillators, filters, FFT, spectrum, windowing & related DSP utils.

Partially ported from other thi.ng projects (e.g. thi.ng/synstack, thi.ng/vexed-generation, toxiclibs).

STABLE - used in production

yarn add @thi.ng/dsp

• @thi.ng/api
• @thi.ng/checks
• @thi.ng/math

Several demos in this repo's /examples directory are using this package.

A selection:

Interactive inverse FFT toy synth

Live demo | Source

Live demo | Source

Live demo | Source

Generated API docs

• add - adder
• alt - alternating values
• constant - constant value
• cosP - trig-free cosine osc
• exp - time-based exponential gain/decay (factory for mul)
• impulse - impulse gen
• line - line gen (factory for add)
• madd - multiply-adder
• mul - multiplier (exponential gain/decay)
• reciprocal - fractional sequence (1, 1/2, 1/3, 1/4 etc.)
• trigger - cyclic impulse

• comp - IGen composition (1-4 inputs)
• addG - higher-order adder
• product - product of input gens
• sum - sum of input gens
• wrapAroundG - folds input gen into given interval

• osc - arbitrary function oscillator
• modOsc - FM / FMAM oscillator

• comb()
• mix() (HOF)
• rect()
• saw()
• sin()
• tri()
• wavetable() (HOF)

Band-limited:

• additive() (HOF)
• squareAdditive()
• sawAdditive()

Trigonometry free sin/cos oscillator / iterator based on a state-variable filter. Only useable for freq < ~2Hz.

• lfo

The following diagrams show various combinations of oscillator signals and their filtered responses (with different cutoff/center frequencies). The red waveform is the original generated 1kHz signal.

All diagrams were generated with this script.

TODO

The bandwidth of each filter is set to 1/2 of its center frequency.

Source

Ringbuffer / delay line for arbitrary values and support for tapping at any relative position.

• DelayLine class

Source

• fft()
• ifft()
• normalizeFFT()
• denormalizeFFT()
• scaleFFT()
• complexArray()
• conjugate()
• spectrumMag()
• spectrumPow() (optionally as dBFS)
• spectrumPhase()
• binFreq()
• freqBin()
• fftFreq()

Source

• window()
• windowRect()
• windowSin()
• windowSinPow()
• windowLanczos()
• windowHann()
• windowHamming()
• windowBlackman()
• windowBlackmanHarris()
• windowNuttal()
• windowBlackmanNuttal()
• windowGauss()

Karsten Schmidt

© 2015 - 2020 Karsten Schmidt // Apache Software License 2.0