91 lines
1.5 KiB
Text
91 lines
1.5 KiB
Text
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#lang scribble/manual
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@(require (for-label racket))
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@title{Prewrite}
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rewriting system@section{related}
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Classes/Pfsm
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@section{categories}
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Streams-Patterns-Events>Patterns>List>Indexing
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@section{description}
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Lindenmayer system pattern for selfsimilar structures. Its strong::dictionary (or event):: maps one element to an array of child elements. The algorithm replaces iteratively (strong::levels:: deep) elements by arrays of elements starting with the values in the strong::pattern::.
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@section{ClassMethods}
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@section{method}
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new
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@section{argument}
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pattern
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starting value
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@section{argument}
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dict
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a dictionary or an event.
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@section{argument}
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levels
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number of levels
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@racketblock[
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IdentityDictionary[
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elem1 -> [ otherElements ],
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elem2 -> [ otherElements ],
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elem2 -> [ otherElements ]
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]
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::
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]
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@section{Examples}
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The examples use the
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@racketblock[():: shortcut for link::Classes/Event::.
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]
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@racketblock[
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(
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a = Prewrite(0, // start with 0
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( 0: #[2,0],
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1: #[0,0,1],
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2: #[1,0,1]
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), 4);
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x = a.asStream;
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30.do({ x.next.postln });
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)
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//Prewrite used as a sequence of pitches:
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(
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SynthDef(\help_sinegrain,
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{ arg out=0, freq=440, sustain=0.05;
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var env;
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env = EnvGen.kr(Env.perc(0.01, sustain, 0.2), doneAction: Done.freeSelf);
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Out.ar(out, SinOsc.ar(freq, 0, env))
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}).add;
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)
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(
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a = Prewrite(0, (
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0: #[2,0],
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1: #[0,0,1],
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2: #[1,0,1]
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), 4).asStream;
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Routine({
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loop({
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Synth(\help_sinegrain, [\freq, (a.next * 5 + 70).midicps]);
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0.1.wait;
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})
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}).play;
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)
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::
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]
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