/usr/share/SuperCollider/HelpSource/Classes/StandardL.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 | class:: StandardL
summary:: Standard map chaotic generator
categories:: UGens>Generators>Chaotic
related:: Classes/StandardN
description::
A linear-interpolating sound generator based on the difference equations:
teletype::
x(n+1) = (x(n) + y(n+1)) % 2pi
y(n+1) = (y(n) + k * sin(x(n))) % 2pi
::
The standard map is an area preserving map of a cylinder discovered by the plasma physicist Boris Chirikov.
sclang code translation:
code::
(
var k = 1, xi = 0.5, yi = 0, size = 64;
plot(size.collect { yi = yi + (k * sin(xi)) % 2pi; xi = (xi + yi) % 2pi; xi - pi * 0.3183098861837907 });
)
::
classmethods::
method:: ar
argument:: freq
Iteration frequency in Hertz
argument:: k
Perturbation amount
argument:: xi
Initial value of x
argument:: yi
Initial value of y
examples::
code::
// vary frequency
{ StandardL.ar(MouseX.kr(20, SampleRate.ir)) * 0.3 }.play(s);
::
code::
// mouse-controlled param
{ StandardL.ar(SampleRate.ir/2, MouseX.kr(0.9,4)) * 0.3 }.play(s);
::
code::
// as a frequency control
{ SinOsc.ar(StandardL.ar(40, MouseX.kr(0.9,4))*800+900)*0.4 }.play(s);
::
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