oscillators - Faust Libraries

# oscillators.lib

This library contains a collection of sound generators. Its official prefix is `os`.

The oscillators library is organized into 9 sections:

- Wave-Table-Based Oscillators
- Low Frequency Oscillators
- Low Frequency Sawtooths
- Alias-Suppressed Sawtooth
- Alias-Suppressed Pulse, Square, and Impulse Trains
- Filter-Based Oscillators
- Waveguide-Resonator-Based Oscillators
- Casio CZ Oscillators
- PolyBLEP-Based Oscillators

#### References

- https://github.com/grame-cncm/faustlibraries/blob/master/oscillators.lib

## Oscillators based on mathematical functions

Note that there is a numerical problem with several phasor functions built using the internal `phasor_imp`. The reason is that the incremental step is smaller than `ma.EPSILON`, which happens with very small frequencies, so it will have no effect when summed to 1, but it will be enough to make the fractional function wrap around when summed to 0. An example of this problem can be observed when running the following code:

`process = os.phasor(1.0, -.001);`

The output of this program is the sequence 1, 0, 1, 0, 1... This happens because the negative incremental step is greater than `-ma.EPSILON`, which will have no effect when summed to 1, but it will be significant enough to make the fractional function wrap around when summed to 0.

The incremental step can be clipped to guarantee that the phasor will always run correctly for its full cycle, otherwise, for increments smaller than `ma.EPSILON`, phasor would initially run but it'd eventually get stuck once the output gets big enough.

All functions using `phasor_imp` are affected by this problem, but a safer version is implemented, and can be used alternatively by setting `SAFE=1` in the environment using explicit sustitution syntax.

For example: `process = os[SAFE=1;].phasor(1.0, -.001);` will use the safer implementation of `phasor_imp`.

## Wave-Table-Based Oscillators

Oscillators using tables. The table size is set by the pl.tablesize constant.

### `(os.)sinwaveform`

Sine waveform ready to use with a `rdtable`.

#### Usage

    sinwaveform(tablesize) : _

Where:

- `tablesize`: the table size

### `(os.)coswaveform`

Cosine waveform ready to use with a `rdtable`.

#### Usage

    coswaveform(tablesize) : _

Where:

- `tablesize`: the table size

### `(os.)phasor`

A simple phasor to be used with a `rdtable`. `phasor` is a standard Faust function.

#### Usage

    phasor(tablesize,freq) : _

Where:

- `tablesize`: the table size
- `freq`: the frequency in Hz

Note that `tablesize` is just a multiplier for the output of a unit-amp phasor so `phasor(1.0, freq)` can be used to generate a phasor output in the range [0, 1[.

### `(os.)hs_phasor`

Hardsyncing phasor to be used with a `rdtable`.

#### Usage

    hs_phasor(tablesize,freq,reset) :  _

Where:

- `tablesize`: the table size
- `freq`: the frequency in Hz
- `reset`: a reset signal, reset phase to 0 when equal to 1

### `(os.)hsp_phasor`

Hardsyncing phasor with selectable phase to be used with a `rdtable`.

#### Usage

    hsp_phasor(tablesize,freq,reset,phase)

Where:

- `tablesize`: the table size
- `freq`: the frequency in Hz
- `reset`: reset the oscillator to phase when equal to 1
- `phase`: phase between 0 and 1

### `(os.)oscsin`

Sine wave oscillator. `oscsin` is a standard Faust function.

#### Usage

    oscsin(freq) : _

Where:

- `freq`: the frequency in Hz

### `(os.)hs_oscsin`

Sin lookup table with hardsyncing phase.

#### Usage

    hs_oscsin(freq,reset) : _

Where:

- `freq`: the frequency in Hz
- `reset`: reset the oscillator to 0 when equal to 1

### `(os.)osccos`

Cosine wave oscillator.

#### Usage

    osccos(freq) : _

Where:

- `freq`: the frequency in Hz

### `(os.)hs_osccos`

Cos lookup table with hardsyncing phase.

#### Usage

    hs_osccos(freq,reset) : _

Where:

- `freq`: the frequency in Hz
- `reset`: reset the oscillator to 0 when equal to 1

### `(os.)oscp`

A sine wave generator with controllable phase.

#### Usage

    oscp(freq,phase) : _

Where:

- `freq`: the frequency in Hz
- `phase`: the phase in radian

### `(os.)osci`

Interpolated phase sine wave oscillator.

#### Usage

    osci(freq) : _

Where:

- `freq`: the frequency in Hz

### `(os.)osc`

Default sine wave oscillator (same as oscsin). `osc` is a standard Faust function.

#### Usage

    osc(freq) : _

Where:

- `freq`: the frequency in Hz

### `(os.)m_oscsin`

Sine wave oscillator based on the `sin` mathematical function.

#### Usage

    m_oscsin(freq) : _

Where:

- `freq`: the frequency in Hz

### `(os.)m_osccos`

Sine wave oscillator based on the `cos` mathematical function.

#### Usage

    m_osccos(freq) : _

Where:

- `freq`: the frequency in Hz

## Low Frequency Oscillators

Low Frequency Oscillators (LFOs) have prefix `lf_` (no aliasing suppression, since it is inaudible at LF). Use `sawN` and its derivatives for audio oscillators with suppressed aliasing.

### `(os.)lf_imptrain`

Unit-amplitude low-frequency impulse train. `lf_imptrain` is a standard Faust function.

#### Usage

    lf_imptrain(freq) : _

Where:

- `freq`: frequency in Hz

### `(os.)lf_pulsetrainpos`

Unit-amplitude nonnegative LF pulse train, duty cycle between 0 and 1.

#### Usage

    lf_pulsetrainpos(freq, duty) : _

Where:

- `freq`: frequency in Hz
- `duty`: duty cycle between 0 and 1

### `(os.)lf_pulsetrain`

Unit-amplitude zero-mean LF pulse train, duty cycle between 0 and 1.

#### Usage

    lf_pulsetrain(freq,duty) : _

Where:

- `freq`: frequency in Hz
- `duty`: duty cycle between 0 and 1

### `(os.)lf_squarewavepos`

Positive LF square wave in [0,1]

#### Usage

    lf_squarewavepos(freq) : _

Where:

- `freq`: frequency in Hz

### `(os.)lf_squarewave`

Zero-mean unit-amplitude LF square wave. `lf_squarewave` is a standard Faust function.

#### Usage

    lf_squarewave(freq) : _

Where:

- `freq`: frequency in Hz

### `(os.)lf_trianglepos`

Positive unit-amplitude LF positive triangle wave.

#### Usage

    lf_trianglepos(freq) : _

Where:

- `freq`: frequency in Hz

### `(os.)lf_triangle`

Positive unit-amplitude LF triangle wave. `lf_triangle` is a standard Faust function.

#### Usage

    lf_triangle(freq) : _

Where:

- `freq`: frequency in Hz

## Low Frequency Sawtooths

Sawtooth waveform oscillators for virtual analog synthesis et al. The 'simple' versions (`lf_rawsaw`, `lf_sawpos` and `saw1`), are mere samplings of the ideal continuous-time ("analog") waveforms. While simple, the aliasing due to sampling is quite audible. The differentiated polynomial waveform family (`saw2`, `sawN`, and derived functions) do some extra processing to suppress aliasing (not audible for very low fundamental frequencies). According to Lehtonen et al. (JASA 2012), the aliasing of `saw2` should be inaudible at fundamental frequencies below 2 kHz or so, for a 44.1 kHz sampling rate and 60 dB SPL presentation level; fundamentals 415 and below required no aliasing suppression (i.e., `saw1` is ok).

### `(os.)lf_rawsaw`

Simple sawtooth waveform oscillator between 0 and period in samples.

#### Usage

    lf_rawsaw(periodsamps) : _

Where:

- `periodsamps`: number of periods per samples

### `(os.)lf_sawpos`

Simple sawtooth waveform oscillator between 0 and 1.

#### Usage

    lf_sawpos(freq) : _

Where:

- `freq`: frequency in Hz

### `(os.)lf_sawpos_phase`

Simple sawtooth waveform oscillator between 0 and 1 with phase control.

#### Usage

    lf_sawpos_phase(freq, phase) : _

Where:

- `freq`: frequency in Hz
- `phase`: phase between 0 and 1

### `(os.)lf_sawpos_reset`

Simple sawtooth waveform oscillator between 0 and 1 with reset.

#### Usage

    lf_sawpos_reset(freq,reset) : _

Where:

- `freq`: frequency in Hz
- `reset`: reset the oscillator to 0 when equal to 1

### `(os.)lf_sawpos_phase_reset`

Simple sawtooth waveform oscillator between 0 and 1 with phase control and reset.

#### Usage

    lf_sawpos_phase_reset(freq,phase,reset) : _

Where:

- `freq`: frequency in Hz
- `phase`: phase between 0 and 1
- `reset`: reset the oscillator to phase when equal to 1

### `(os.)lf_saw`

Simple sawtooth waveform oscillator between -1 and 1. `lf_saw` is a standard Faust function.

#### Usage

    lf_saw(freq) : _

Where:

- `freq`: frequency in Hz

## Alias-Suppressed Sawtooth

### `(os.)sawN`

Alias-Suppressed Sawtooth Audio-Frequency Oscillator using Nth-order polynomial transitions to reduce aliasing.

`sawN(N,freq)`, `sawNp(N,freq,phase)`, `saw2dpw(freq)`, `saw2(freq)`, `saw3(freq)`, `saw4(freq)`, `sawtooth(freq)`, `saw2f2(freq)`, `saw2f4(freq)`

#### Usage

    sawN(N,freq) : _        // Nth-order aliasing-suppressed sawtooth using DPW method (see below)
    sawNp(N,freq,phase) : _ // sawN with phase offset feature
    saw2dpw(freq) : _       // saw2 using DPW
    saw2ptr(freq) : _       // saw2 using the faster, stateless PTR method
    saw2(freq) : _          // DPW method, but subject to change if a better method emerges
    saw3(freq) : _          // sawN(3)
    saw4(freq) : _          // sawN(4)
    sawtooth(freq) : _      // saw2
    saw2f2(freq) : _        // saw2dpw with 2nd-order droop-correction filtering
    saw2f4(freq) : _        // saw2dpw with 4th-order droop-correction filtering

Where:

- `N`: polynomial order, a constant numerical expression between 1 and 4
- `freq`: frequency in Hz
- `phase`: phase between 0 and 1

#### Method

Differentiated Polynomial Wave (DPW).

##### Reference

"Alias-Suppressed Oscillators based on Differentiated Polynomial Waveforms", Vesa Valimaki, Juhan Nam, Julius Smith, and Jonathan Abel, IEEE Tr. Audio, Speech, and Language Processing (IEEE-ASLP), Vol. 18, no. 5, pp 786-798, May 2010. 10.1109/TASL.2009.2026507.

#### Notes

The polynomial order `N` is limited to 4 because noise has been observed at very low `freq` values. (LFO sawtooths should of course be generated using `lf_sawpos` instead.)

### `(os.)sawNp`

Same as `(os.)sawN` but with a controllable waveform phase.

#### Usage

    sawNp(N,freq,phase) : _

where

- `N`: waveform interpolation polynomial order 1 to 4 (constant integer expression)
- `freq`: frequency in Hz
- `phase`: waveform phase as a fraction of one period (rounded to nearest sample)

#### Implementation Notes

The phase offset is implemented by delaying `sawN(N,freq)` by `round(phase*ma.SR/freq)` samples, for up to 8191 samples. The minimum sawtooth frequency that can be delayed a whole period is therefore `ma.SR/8191`, which is well below audibility for normal audio sampling rates.

### `(os.)saw2, (os.)saw3, (os.)saw4`

Alias-Suppressed Sawtooth Audio-Frequency Oscillators of order 2, 3, 4.

#### Usage

    saw2(freq) : _
    saw3(freq) : _
    saw4(freq) : _

where

- `freq`: frequency in Hz

##### References

See `sawN` above.

#### Implementation Notes

Presently, only `saw2` uses the PTR method, while `saw3` and `saw4` use DPW. This is because PTR has been implemented and tested for the 2nd-order case only.

### `(os.)saw2ptr`

Alias-Suppressed Sawtooth Audio-Frequency Oscillator using Polynomial Transition Regions (PTR) for order 2.

#### Usage

    saw2ptr(freq) : _

where

- `freq`: frequency in Hz

##### Implementation

Polynomial Transition Regions (PTR) method for aliasing suppression.

##### References

- Kleimola, J.; Valimaki, V., "Reducing Aliasing from Synthetic Audio Signals Using Polynomial Transition Regions," in Signal Processing Letters, IEEE , vol.19, no.2, pp.67-70, Feb. 2012
- https://aaltodoc.aalto.fi/bitstream/handle/123456789/7747/publication6.pdf?sequence=9
- http://research.spa.aalto.fi/publications/papers/spl-ptr/

##### Notes

Method PTR may be preferred because it requires less computation and is stateless which means that the frequency `freq` can be modulated arbitrarily fast over time without filtering artifacts. For this reason, `saw2` is presently defined as `saw2ptr`.

### `(os.)saw2dpw`

Alias-Suppressed Sawtooth Audio-Frequency Oscillator using the Differentiated Polynomial Waveform (DWP) method.

#### Usage

    saw2dpw(freq) : _

where

- `freq`: frequency in Hz

This is the original Faust `saw2` function using the DPW method. Since `saw2` is now defined as `saw2ptr`, the DPW version is now available as `saw2dwp`.

### `(os.)sawtooth`

Alias-suppressed aliasing-suppressed sawtooth oscillator, presently defined as `saw2`. `sawtooth` is a standard Faust function.

#### Usage

    sawtooth(freq) : _

with

- `freq`: frequency in Hz

### `(os.)saw2f2, (os.)saw2f4`

Alias-Suppressed Sawtooth Audio-Frequency Oscillator with Order 2 or 4 Droop Correction Filtering.

#### Usage

    saw2f2(freq) : _
    saw2f4(freq) : _

with

- `freq`: frequency in Hz

In return for aliasing suppression, there is some attenuation near half the sampling rate. This can be considered as beneficial, or it can be compensated with a high-frequency boost. The boost filter is second-order for `saw2f2` and fourth-order for `saw2f4`, and both are designed for the DWP case and therefore use `saw2dpw`. See Figure 4(b) in the DPW reference for a plot of the slight droop in the DPW case.

## Alias-Suppressed Pulse, Square, and Impulse Trains

Alias-Suppressed Pulse, Square and Impulse Trains.

`pulsetrainN`, `pulsetrain`, `squareN`, `square`, `imptrainN`, `imptrain`, `triangleN`, `triangle`

All are zero-mean and meant to oscillate in the audio frequency range. Use simpler sample-rounded `lf_*` versions above for LFOs.

#### Usage

    pulsetrainN(N,freq,duty) : _
    pulsetrain(freq, duty) : _ // = pulsetrainN(2)

    squareN(N,freq) : _
    square : _ // = squareN(2)

    imptrainN(N,freq) : _
    imptrain : _ // = imptrainN(2)

    triangleN(N,freq) : _
    triangle : _ // = triangleN(2)

Where:

- `N`: polynomial order, a constant numerical expression
- `freq`: frequency in Hz

### `(os.)impulse`

One-time impulse generated when the Faust process is started. `impulse` is a standard Faust function.

#### Usage

    impulse : _

### `(os.)pulsetrainN`

Alias-suppressed pulse train oscillator.

#### Usage

    pulsetrainN(N,freq,duty) : _

Where:

- `N`: order, as a constant numerical expression
- `freq`: frequency in Hz
- `duty`: duty cycle between 0 and 1

### `(os.)pulsetrain`

Alias-suppressed pulse train oscillator. Based on `pulsetrainN(2)`. `pulsetrain` is a standard Faust function.

#### Usage

    pulsetrain(freq,duty) : _

Where:

- `freq`: frequency in Hz
- `duty`: duty cycle between 0 and 1

### `(os.)squareN`

Alias-suppressed square wave oscillator.

#### Usage

    squareN(N,freq) : _

Where:

- `N`: order, as a constant numerical expression
- `freq`: frequency in Hz

### `(os.)square`

Alias-suppressed square wave oscillator. Based on `squareN(2)`. `square` is a standard Faust function.

#### Usage

    square(freq) : _

Where:

- `freq`: frequency in Hz

### `(os.)imptrainN`

Alias-suppressed impulse train generator.

#### Usage

    imptrainN(N,freq) : _

Where:

- `N`: order, as a constant numerical expression
- `freq`: frequency in Hz

### `(os.)imptrain`

Alias-suppressed impulse train generator. Based on `imptrainN(2)`. `imptrain` is a standard Faust function.

#### Usage

    imptrain(freq) : _

Where:

- `freq`: frequency in Hz

### `(os.)triangleN`

Alias-suppressed triangle wave oscillator.

#### Usage

    triangleN(N,freq) : _

Where:

- `N`: order, as a constant numerical expression
- `freq`: frequency in Hz

### `(os.)triangle`

Alias-suppressed triangle wave oscillator. Based on `triangleN(2)`. `triangle` is a standard Faust function.

#### Usage

    triangle(freq) : _

Where:

- `freq`: frequency in Hz

## Filter-Based Oscillators

Filter-Based Oscillators.

#### Usage

    osc[b|rq|rs|rc|s](freq), where freq = frequency in Hz.

#### References

- http://lac.linuxaudio.org/2012/download/lac12-slides-jos.pdf
- https://ccrma.stanford.edu/~jos/pdf/lac12-paper-jos.pdf

### `(os.)oscb`

Sinusoidal oscillator based on the biquad.

#### Usage

    oscb(freq) : _

Where:

- `freq`: frequency in Hz

### `(os.)oscrq`

Sinusoidal (sine and cosine) oscillator based on 2D vector rotation, = undamped "coupled-form" resonator = lossless 2nd-order normalized ladder filter.

#### Usage

    oscrq(freq) : _,_

Where:

- `freq`: frequency in Hz

#### Reference

- https://ccrma.stanford.edu/~jos/pasp/Normalized_Scattering_Junctions.html

### `(os.)oscrs`

Sinusoidal (sine) oscillator based on 2D vector rotation, = undamped "coupled-form" resonator = lossless 2nd-order normalized ladder filter.

#### Usage

    oscrs(freq) : _

Where:

- `freq`: frequency in Hz

#### Reference

- https://ccrma.stanford.edu/~jos/pasp/Normalized_Scattering_Junctions.html

### `(os.)oscrc`

Sinusoidal (cosine) oscillator based on 2D vector rotation, = undamped "coupled-form" resonator = lossless 2nd-order normalized ladder filter.

#### Usage

    oscrc(freq) : _

Where:

- `freq`: frequency in Hz

#### Reference

- https://ccrma.stanford.edu/~jos/pasp/Normalized_Scattering_Junctions.html

### `(os.)oscs`

Sinusoidal oscillator based on the state variable filter = undamped "modified-coupled-form" resonator = "magic circle" algorithm used in graphics.

#### Usage

    oscs(freq) : _

Where:

- `freq`: frequency in Hz

### `(os.)quadosc`

Quadrature (cosine and sine) oscillator based on QuadOsc by Martin Vicanek.

#### Usage

    quadosc(freq) : _,_

where

- `freq`: frequency in Hz

#### Reference

- https://vicanek.de/articles/QuadOsc.pdf

### `(os.)sidebands`

Adds harmonics to quad oscillator.

#### Usage

       cos(x),sin(x) : sidebands(vs) : _,_

Where:

- `vs` : list of amplitudes

#### Example test program

       cos(x),sin(x) : sidebands((10,20,30))

outputs:

       10*cos(x) + 20*cos(2*x) + 30*cos(3*x),
       10*sin(x) + 20*sin(2*x) + 30*sin(3*x);

The following:

       process = os.quadosc(F) : sidebands((10,20,30))

is (modulo floating point issues) the same as:

       c = os.quadosc : _,!;
       s = os.quadosc : !,_;
       process =
           10*c(F) + 20*c(2*F) + 30*c(F),
           10*s(F) + 20*s(2*F) + 30*s(F);

but much more efficient.

#### Implementation Notes

This is based on the trivial trigonometric identities:

       cos((n + 1) x) = 2 cos(x) cos(n x) - cos((n - 1) x)
       sin((n + 1) x) = 2 cos(x) sin(n x) - sin((n - 1) x)

Note that the calculation of the cosine/sine parts do not depend on each other, so if you only need the sine part you can do:

       process = os.quadosc(F) : sidebands(vs) : !,_;

and the compiler will discard the half of the calculations.

### `(os.)sidebands_list`

Creates the list of complex harmonics from quad oscillator.

Similar to `sidebands` but doesn't sum the harmonics, so it is more generic but less convenient for immediate usage.

#### Usage

       cos(x),sin(x) : sidebands_list(N) : si.bus(2*N)

Where:

- `N` : number of harmonics, compile time constant > 1

#### Example test program

       cos(x),sin(x) : sidebands_list(3)

outputs:

       cos(x),sin(x), cos(2*x),sin(2*x), cos(3*x),sin(3*x);

The following:

       process = os.quadosc(F) : sidebands_list(3)

is (modulo floating point issues) the same as:

       process = os.quadosc(F), os.quadosc(2*F), os.quadosc(3*F);

but much more efficient.

## Waveguide-Resonator-Based Oscillators

Sinusoidal oscillator based on the waveguide resonator `wgr`.

### `(os.)oscwc`

Sinusoidal oscillator based on the waveguide resonator `wgr`. Unit-amplitude cosine oscillator.

#### Usage

    oscwc(freq) : _

Where:

- `freq`: frequency in Hz

#### Reference

- https://ccrma.stanford.edu/~jos/pasp/Digital_Waveguide_Oscillator.html

### `(os.)oscws`

Sinusoidal oscillator based on the waveguide resonator `wgr`. Unit-amplitude sine oscillator.

#### Usage

    oscws(freq) : _

Where:

- `freq`: frequency in Hz

#### Reference

- https://ccrma.stanford.edu/~jos/pasp/Digital_Waveguide_Oscillator.html

### `(os.)oscq`

Sinusoidal oscillator based on the waveguide resonator `wgr`. Unit-amplitude cosine and sine (quadrature) oscillator.

#### Usage

    oscq(freq) : _,_

Where:

- `freq`: frequency in Hz

#### Reference

- https://ccrma.stanford.edu/~jos/pasp/Digital_Waveguide_Oscillator.html

### `(os.)oscw`

Sinusoidal oscillator based on the waveguide resonator `wgr`. Unit-amplitude cosine oscillator (default).

#### Usage

    oscw(freq) : _

Where:

- `freq`: frequency in Hz

#### Reference

- https://ccrma.stanford.edu/~jos/pasp/Digital_Waveguide_Oscillator.html

## Casio CZ Oscillators

Oscillators that mimic some of the Casio CZ oscillators.

There are two sets:

- a set with an index parameter

- a set with a res parameter

The "index oscillators" outputs a sine wave at index=0 and gets brighter with a higher index. There are two versions of the "index oscillators":

- with P appended to the name: is phase aligned with `fund:sin`

- without P appended to the name: has the phase of the original CZ oscillators

The "res oscillators" have a resonant frequency. "res" is the frequency of resonance as a factor of the fundamental pitch.

For the `fund` waveform, use a low-frequency oscillator without anti-aliasing such as `os.lf_saw`.

### `(os.)CZsaw`

Oscillator that mimics the Casio CZ saw oscillator. `CZsaw` is a standard Faust function.

#### Usage

    CZsaw(fund,index) : _

Where:

- `fund`: a saw-tooth waveform between 0 and 1 that the oscillator slaves to
- `index`: the brightness of the oscillator, 0 to 1. 0 = sine-wave, 1 = saw-wave

### `(os.)CZsawP`

Oscillator that mimics the Casio CZ saw oscillator, with it's phase aligned to `fund:sin`. `CZsawP` is a standard Faust function.

#### Usage

    CZsawP(fund,index) : _

Where:

- `fund`: a saw-tooth waveform between 0 and 1 that the oscillator slaves to
- `index`: the brightness of the oscillator, 0 to 1. 0 = sine-wave, 1 = saw-wave

### `(os.)CZsquare`

Oscillator that mimics the Casio CZ square oscillator `CZsquare` is a standard Faust function.

#### Usage

    CZsquare(fund,index) : _

Where:

- `fund`: a saw-tooth waveform between 0 and 1 that the oscillator slaves to
- `index`: the brightness of the oscillator, 0 to 1. 0 = sine-wave, 1 = square-wave

### `(os.)CZsquareP`

Oscillator that mimics the Casio CZ square oscillator, with it's phase aligned to `fund:sin`. `CZsquareP` is a standard Faust function.

#### Usage

    CZsquareP(fund,index) : _

Where:

- `fund`: a saw-tooth waveform between 0 and 1 that the oscillator slaves to
- `index`: the brightness of the oscillator, 0 to 1. 0 = sine-wave, 1 = square-wave

### `(os.)CZpulse`

Oscillator that mimics the Casio CZ pulse oscillator. `CZpulse` is a standard Faust function.

#### Usage

    CZpulse(fund,index) : _

Where:

- `fund`: a saw-tooth waveform between 0 and 1 that the oscillator slaves to
- `index`: the brightness of the oscillator, 0 gives a sine-wave, 1 is closer to a pulse

### `(os.)CZpulseP`

Oscillator that mimics the Casio CZ pulse oscillator, with it's phase aligned to `fund:sin`. `CZpulseP` is a standard Faust function.

#### Usage

    CZpulseP(fund,index) : _

Where:

- `fund`: a saw-tooth waveform between 0 and 1 that the oscillator slaves to
- `index`: the brightness of the oscillator, 0 gives a sine-wave, 1 is closer to a pulse

### `(os.)CZsinePulse`

Oscillator that mimics the Casio CZ sine/pulse oscillator. `CZsinePulse` is a standard Faust function.

#### Usage

    CZsinePulse(fund,index) : _

Where:

- `fund`: a saw-tooth waveform between 0 and 1 that the oscillator slaves to
- `index`: the brightness of the oscillator, 0 gives a sine-wave, 1 is a sine minus a pulse

### `(os.)CZsinePulseP`

Oscillator that mimics the Casio CZ sine/pulse oscillator, with it's phase aligned to `fund:sin`. `CZsinePulseP` is a standard Faust function.

#### Usage

    CZsinePulseP(fund,index) : _

Where:

- `fund`: a saw-tooth waveform between 0 and 1 that the oscillator slaves to
- `index`: the brightness of the oscillator, 0 gives a sine-wave, 1 is a sine minus a pulse

### `(os.)CZhalfSine`

Oscillator that mimics the Casio CZ half sine oscillator. `CZhalfSine` is a standard Faust function.

#### Usage

    CZhalfSine(fund,index) : _

Where:

- `fund`: a saw-tooth waveform between 0 and 1 that the oscillator slaves to
- `index`: the brightness of the oscillator, 0 gives a sine-wave, 1 is somewhere between a saw and a square

### `(os.)CZhalfSineP`

Oscillator that mimics the Casio CZ half sine oscillator, with it's phase aligned to `fund:sin`. `CZhalfSineP` is a standard Faust function.

#### Usage

    CZhalfSineP(fund,index) : _

Where:

- `fund`: a saw-tooth waveform between 0 and 1 that the oscillator slaves to
- `index`: the brightness of the oscillator, 0 gives a sine-wave, 1 is somewhere between a saw and a square

### `(os.)CZresSaw`

Oscillator that mimics the Casio CZ resonant sawtooth oscillator. `CZresSaw` is a standard Faust function.

#### Usage

    CZresSaw(fund,res) : _

Where:

- `fund`: a saw-tooth waveform between 0 and 1 that the oscillator slaves to
- `res`: the frequency of resonance as a factor of the fundamental pitch.

### `(os.)CZresTriangle`

Oscillator that mimics the Casio CZ resonant triangle oscillator. `CZresTriangle` is a standard Faust function.

#### Usage

    CZresTriangle(fund,res) : _

Where:

- `fund`: a saw-tooth waveform between 0 and 1 that the oscillator slaves to
- `res`: the frequency of resonance as a factor of the fundamental pitch.

### `(os.)CZresTrap`

Oscillator that mimics the Casio CZ resonant trapeze oscillator `CZresTrap` is a standard Faust function.

#### Usage

    CZresTrap(fund,res) : _

Where:

- `fund`: a saw-tooth waveform between 0 and 1 that the oscillator slaves to
- `res`: the frequency of resonance as a factor of the fundamental pitch.

## PolyBLEP-Based Oscillators

### `(os.)polyblep`

PolyBLEP residual function, used for smoothing steps in the audio signal.

#### Usage

    polyblep(Q,phase) : _

Where:

- `Q`: smoothing factor between 0 and 0.5. Determines how far from the ends of the phase interval the quadratic function is used.
- `phase`: normalised phase (between 0 and 1)

### `(os.)polyblep_saw`

Sawtooth oscillator with suppressed aliasing (using `polyblep`).

#### Usage

    polyblep_saw(freq) : _

Where:

- `freq`: frequency in Hz

### `(os.)polyblep_square`

Square wave oscillator with suppressed aliasing (using `polyblep`).

#### Usage

    polyblep_square(freq) : _

Where:

- `freq`: frequency in Hz

### `(os.)polyblep_triangle`

Triangle wave oscillator with suppressed aliasing (using `polyblep`).

#### Usage

    polyblep_triangle(freq) : _

Where:

- `freq`: frequency in Hz

#### Search

From here you can search these documents. Enter your search terms below.

#### Keyboard Shortcuts

Keys | Action
--- | ---
`?` | Open this help
`n` | Next page
`p` | Previous page
`s` | Search