/usr/share/SuperCollider/HelpSource/Classes/FBSineC.schelp is in supercollider-common 1:3.8.0~repack-2.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 | class:: FBSineC
summary:: Feedback sine with chaotic phase indexing
categories:: UGens>Generators>Chaotic
related:: Classes/FBSineN, Classes/FBSineL
description::
A cubic-interpolating sound generator based on the difference equations:
teletype::
x(n+1) = sin(im * y(n) + fb * x(n))
y(n+1) = (a * y(n) + c) % 2pi
::
This uses a linear congruential function to drive the phase indexing of a sine wave. For code:: im = 1 ::, code:: fb = 0 ::, and code:: a = 1 :: a normal sinewave results.
sclang code translation:
code::
(
var im = 1, fb = 0.1, a = 1.1, c = 0.5, xi = 0.1, yi = 0.1, size = 64;
plot(size.collect { xi = sin((im * yi) + (fb * xi)); yi = (a * yi + c) % 2pi; xi });
)
::
classmethods::
method:: ar
argument:: freq
Iteration frequency in Hertz
argument:: im
Index multiplier amount
argument:: fb
Feedback amount
argument:: a
Phase multiplier amount
argument:: c
Phase increment amount
argument:: xi
Initial value of x
argument:: yi
Initial value of y
examples::
code::
// default initial params
{ FBSineC.ar(SampleRate.ir/4) * 0.2 }.play(s);
::
code::
// increase feedback
{ FBSineC.ar(SampleRate.ir, 1, Line.kr(0.01, 4, 10), 1, 0.1) * 0.2 }.play(s);
::
code::
// increase phase multiplier
{ FBSineC.ar(SampleRate.ir, 1, 0, XLine.kr(1, 2, 10), 0.1) * 0.2 }.play(s);
::
code::
// modulate frequency and index multiplier
{ FBSineC.ar(LFNoise2.kr(1, 1e4, 1e4), LFNoise2.kr(1,16,17), 1, 1.005, 0.7) * 0.2 }.play(s);
::
code::
// randomly modulate params
(
{ FBSineC.ar(
LFNoise2.kr(1, 1e4, 1e4),
LFNoise2.kr(1, 32, 33),
LFNoise2.kr(1, 0.5),
LFNoise2.kr(1, 0.05, 1.05),
LFNoise2.kr(1, 0.3, 0.3)
) * 0.2 }.play(s);
)
::
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