72 lines
1.2 KiB
Racket
72 lines
1.2 KiB
Racket
#lang scribble/manual
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@(require (for-label racket))
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@title{StandardL}
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Standard map chaotic generator@section{categories}
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UGens>Generators>Chaotic
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@section{related}
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Classes/StandardN
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@section{description}
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A linear-interpolating sound generator based on the difference equations:
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teletype::
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x(n+1) = (x(n) + y(n+1)) % 2pi
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y(n+1) = (y(n) + k * sin(x(n))) % 2pi
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::
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The standard map is an area preserving map of a cylinder discovered by the plasma physicist Boris Chirikov.
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sclang code translation:
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@racketblock[
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(
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var k = 1, xi = 0.5, yi = 0, size = 64;
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plot(size.collect { yi = yi + (k * sin(xi)) % 2pi; xi = (xi + yi) % 2pi; xi - pi * 0.3183098861837907 });
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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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k
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Perturbation amount
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@section{argument}
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xi
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Initial value of x
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@section{argument}
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yi
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Initial value of y
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@section{examples}
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@racketblock[
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// vary frequency
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{ StandardL.ar(MouseX.kr(20, SampleRate.ir)) * 0.3 }.play(s);
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::
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]
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@racketblock[
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// mouse-controlled param
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{ StandardL.ar(SampleRate.ir/2, MouseX.kr(0.9,4)) * 0.3 }.play(s);
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::
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]
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@racketblock[
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// as a frequency control
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{ SinOsc.ar(StandardL.ar(40, MouseX.kr(0.9,4))*800+900)*0.4 }.play(s);
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::
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]
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