HelpSource/Classes/Prewrite.schelp

   1 class:: Prewrite
   2 summary:: rewriting system
   3 related:: Classes/Pfsm
   4 categories:: Streams-Patterns-Events>Patterns>List>Indexing
   5
   6 description::
   7
   8 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::.
   9
  10 ClassMethods::
  11
  12 method::new
  13
  14 argument::pattern
  15 starting value
  16
  17 argument::dict
  18 a dictionary or an event.
  19
  20 argument::levels
  21 number of levels
  22
  23 code::
  24 IdentityDictionary[
  25         elem1 -> [ otherElements ],
  26         elem2 -> [ otherElements ],
  27         elem2 -> [ otherElements ]
  28 ]
  29 ::
  30
  31 Examples::
  32
  33 The examples use the code::():: shortcut for link::Classes/Event::.
  34
  35 code::
  36 (
  37 a = Prewrite(0, // start with 0
  38                 (       0: #[2,0],
  39                         1: #[0,0,1],
  40                         2: #[1,0,1]
  41                 ), 4);
  42 x = a.asStream;
  43 30.do({ x.next.postln });
  44 )
  45
  46
  47 //Prewrite used as a sequence of pitches:
  48
  49 (
  50 SynthDef(\help_sinegrain,
  51         { arg out=0, freq=440, sustain=0.05;
  52                 var env;
  53                 env = EnvGen.kr(Env.perc(0.01, sustain, 0.2), doneAction:2);
  54                 Out.ar(out, SinOsc.ar(freq, 0, env))
  55         }).add;
  56 )
  57
  58 (
  59 a = Prewrite(0, (
  60         0: #[2,0],
  61         1: #[0,0,1],
  62         2: #[1,0,1]
  63 ), 4).asStream;
  64 Routine({
  65         loop({
  66                 Synth(\help_sinegrain, [\freq, (a.next * 5 + 70).midicps]);
  67                 0.1.wait;
  68         })
  69 }).play;
  70 )
  71 ::