74 lines
909 B
Text
74 lines
909 B
Text
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#lang scribble/manual
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@(require (for-label racket))
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@title{HPZ1}
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Two point difference filter@section{related}
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Classes/LPZ1, Classes/HPZ2
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@section{categories}
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UGens>Filters>Linear
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@section{description}
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A special case fixed filter. Implements the formula:
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@racketblock[
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out(i) = 0.5 * (in(i) - in(i-1))
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::
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Which is a two point differentiator.
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]
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@section{classmethods}
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@section{method}
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ar, kr
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@section{argument}
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in
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The input signal.
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@section{argument}
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mul
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Output will be multiplied by this value.
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@section{argument}
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add
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This value will be added to the output.
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@section{Examples}
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@racketblock[
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// Compare:
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{ WhiteNoise.ar(0.25) }.play;
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{ HPZ1.ar(WhiteNoise.ar(0.25)) }.play;
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// HPZ1 is useful to detect changes in a signal:
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// see also HPZ2
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(
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{
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var changingSignal = LFNoise0.ar(1000);
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var hpz1 = HPZ1.ar(changingSignal);
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[hpz1, hpz1 > 0, hpz1.abs > 0]
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}.plot
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);
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::
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]
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