77 lines
1.6 KiB
Text
77 lines
1.6 KiB
Text
class:: FBSineN
|
|
summary:: Feedback sine with chaotic phase indexing
|
|
categories:: UGens>Generators>Chaotic
|
|
related:: Classes/FBSineL, Classes/FBSineC
|
|
|
|
description::
|
|
A non-interpolating sound generator based on the difference equations:
|
|
|
|
teletype::
|
|
x(n+1) = sin(im * y(n) + fb * x(n))
|
|
y(n+1) = (a * y(n) + c) % 2pi
|
|
::
|
|
|
|
|
|
This uses a linear congruential function to drive the phase indexing of a sine wave. For code:: im = 1 ::, code:: fb = 0 ::, and code:: a = 1 :: a normal sinewave results.
|
|
|
|
sclang code translation:
|
|
|
|
code::
|
|
(
|
|
var im = 1, fb = 0.1, a = 1.1, c = 0.5, xi = 0.1, yi = 0.1, size = 64;
|
|
plot(size.collect { xi = sin((im * yi) + (fb * xi)); yi = (a * yi + c) % 2pi; xi });
|
|
)
|
|
::
|
|
|
|
classmethods::
|
|
method:: ar
|
|
argument:: freq
|
|
Iteration frequency in Hertz
|
|
argument:: im
|
|
Index multiplier amount
|
|
argument:: fb
|
|
Feedback amount
|
|
argument:: a
|
|
Phase multiplier amount
|
|
argument:: c
|
|
Phase increment amount
|
|
argument:: xi
|
|
Initial value of x
|
|
argument:: yi
|
|
Initial value of y
|
|
argument:: mul
|
|
argument:: add
|
|
|
|
examples::
|
|
code::
|
|
// default initial params
|
|
{ FBSineN.ar(SampleRate.ir/4) * 0.2 }.play(s);
|
|
::
|
|
|
|
code::
|
|
// increase feedback
|
|
{ FBSineN.ar(SampleRate.ir, 1, Line.kr(0.01, 4, 10), 1, 0.1) * 0.2 }.play(s);
|
|
::
|
|
|
|
code::
|
|
// increase phase multiplier
|
|
{ FBSineN.ar(SampleRate.ir, 1, 0, XLine.kr(1, 2, 10), 0.1) * 0.2 }.play(s);
|
|
::
|
|
|
|
code::
|
|
// modulate frequency and index multiplier
|
|
{ FBSineN.ar(LFNoise2.kr(1, 1e4, 1e4), LFNoise2.kr(1,16,17), 1, 1.005, 0.7) * 0.2 }.play(s);
|
|
::
|
|
|
|
code::
|
|
// randomly modulate params
|
|
(
|
|
{ FBSineN.ar(
|
|
LFNoise2.kr(1, 1e4, 1e4),
|
|
LFNoise2.kr(1, 32, 33),
|
|
LFNoise2.kr(1, 0.5),
|
|
LFNoise2.kr(1, 0.05, 1.05),
|
|
LFNoise2.kr(1, 0.3, 0.3)
|
|
) * 0.2 }.play(s);
|
|
)
|
|
::
|