83 lines
1.6 KiB
Text
83 lines
1.6 KiB
Text
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#lang scribble/manual
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@(require (for-label racket))
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@title{Pseed}
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set the random seed in subpattern@section{related}
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Reference/randomSeed
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@section{categories}
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Streams-Patterns-Events>Patterns>Language Control
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@section{description}
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Set the random generator seed of the resulting stream.
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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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randSeed
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integer number, pattern or stream that return an integer number.
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@section{note}
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randSeed is always treated as a pattern/stream. If you provide a single, constant seed value, it will behave as an infinite-length stream. This will cause the subpattern to be embedded an infinite number of times. Compare:
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@racketblock[
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// Pwhite repeats its three values forever
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Pseed(1000, Pwhite(1, 10, 3)).asStream.nextN(10);
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// Pwhite runs once:
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// the output stream consists of three values, then 'nil' ad infinitum
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Pseed(Pn(1000, 1), Pwhite(1, 10, 3)).asStream.nextN(10);
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::
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::
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]
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@section{argument}
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pattern
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@section{Examples}
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@racketblock[
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a = Pseed(1972, Prand([1,2,3], inf));
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b = a.asStream;
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10.do({ b.next.post });
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c = a.asStream;
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10.do({ c.next.post });
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// using a seed pattern as input:
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a = Pseed(Pseq([1812, 1912], inf), Prand([1,2,3], 5));
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b = a.asStream;
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2.do({ 5.do({ b.next.post });"".postln; });
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c = a.asStream;
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2.do({ 5.do({ c.next.post });"".postln; });
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// outer thread is independant:
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a = Pseed(Prand([1534, 1600, 1798, 1986, 2005], inf), Pshuf([1, Prand([7, 9], 2), 1, 2, 3], 1));
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// returns random streams
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b = a.asStream;
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2.do({ 5.do({ b.next.post });"".postln; });
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c = a.asStream;
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2.do({ 5.do({ c.next.post });"".postln; });
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::
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]
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