80 lines
1.4 KiB
Text
80 lines
1.4 KiB
Text
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#lang scribble/manual
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@(require (for-label racket))
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@title{HenonN}
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Henon map chaotic generator@section{categories}
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UGens>Generators>Chaotic
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@section{related}
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Classes/HenonL, Classes/HenonC
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@section{description}
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A non-interpolating sound generator based on the difference equation:
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teletype::
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x(n+2) = 1 - a * x(n+1)^2 + b * x(n)
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::
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This equation was discovered by French astronomer Michel Hénon while studying the orbits of stars in globular clusters.
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sclang code translation:
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@racketblock[
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(
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var a = 1.4, b = 0.3, x0 = 0, x1 = 1, size = 64;
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plot(size.collect { var aux = 1 - (a * (x1 ** 2)) + (b * x0); x0 = x1; x1 = aux; aux });
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)
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::
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]
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@section{classmethods}
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@section{method}
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ar
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@section{argument}
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freq
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Iteration frequency in Hertz
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@section{argument}
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a
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Equation variable
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@section{argument}
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b
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Equation variable
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@section{argument}
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x0
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Initial value of x
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@section{argument}
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x1
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Second value of x
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@section{argument}
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mul
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@section{argument}
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add
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@section{examples}
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@racketblock[
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// default initial params
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{ HenonN.ar(MouseX.kr(20, SampleRate.ir)) * 0.2 }.play(s);
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// mouse-control of params
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{ HenonN.ar(SampleRate.ir/4, MouseX.kr(1,1.4), MouseY.kr(0,0.3)) * 0.2 }.play(s);
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// randomly modulate params
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(
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{ HenonN.ar(
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SampleRate.ir/8,
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LFNoise2.kr(1, 0.2, 1.2),
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LFNoise2.kr(1, 0.15, 0.15)
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) * 0.2 }.play(s);
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)
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// as a frequency control
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{ SinOsc.ar(HenonN.ar(40, MouseX.kr(1,1.4), MouseY.kr(0,0.3))*800+900)*0.4 }.play(s);
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::
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]
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