87 lines
1.3 KiB
Racket
87 lines
1.3 KiB
Racket
#lang scribble/manual
|
|
@(require (for-label racket))
|
|
|
|
@title{QuadN}
|
|
General quadratic map chaotic generator@section{categories}
|
|
UGens>Generators>Chaotic
|
|
@section{related}
|
|
Classes/QuadL, Classes/QuadC
|
|
|
|
@section{description}
|
|
|
|
A non-interpolating sound generator based on the difference equation:
|
|
|
|
teletype::
|
|
x(n+1) = a * x(n)^2 + b * x(n) + c
|
|
::
|
|
|
|
sclang code translation:
|
|
|
|
|
|
@racketblock[
|
|
(
|
|
var a = 1, b = -1, c = -0.75, xi = 0, size = 64;
|
|
plot(size.collect { xi = (a * (xi ** 2)) + (b * xi) + c; xi });
|
|
)
|
|
::
|
|
|
|
]
|
|
@section{classmethods}
|
|
|
|
@section{method}
|
|
ar
|
|
@section{argument}
|
|
freq
|
|
Iteration frequency in Hertz
|
|
@section{argument}
|
|
a
|
|
Equation variable
|
|
@section{argument}
|
|
b
|
|
Equation variable
|
|
@section{argument}
|
|
c
|
|
Equation variable
|
|
@section{argument}
|
|
xi
|
|
Initial value of x
|
|
@section{argument}
|
|
mul
|
|
@section{argument}
|
|
add
|
|
|
|
@section{examples}
|
|
|
|
|
|
@racketblock[
|
|
// default params
|
|
{ QuadN.ar(SampleRate.ir/4) * 0.2 }.play(s);
|
|
::
|
|
|
|
]
|
|
|
|
@racketblock[
|
|
// logistic map
|
|
// equation: x1 = -r*x0^2 + r*x0
|
|
(
|
|
{ var r;
|
|
r = MouseX.kr(3.5441, 4); // stable range
|
|
QuadN.ar(SampleRate.ir/4, r.neg, r, 0, 0.1) * 0.4;
|
|
}.play(s);
|
|
)
|
|
::
|
|
|
|
]
|
|
|
|
@racketblock[
|
|
// logistic map as frequency control
|
|
(
|
|
{ var r;
|
|
r = MouseX.kr(3.5441, 4); // stable range
|
|
SinOsc.ar(QuadN.ar(40, r.neg, r, 0, 0.1, 800, 900)) * 0.4;
|
|
}.play(s);
|
|
)
|
|
::
|
|
]
|
|
|
|
|