PSrecur | SuperCollider 3.13.0 Help

Class Methods

.new

Creates a new PSrecur object.

Arguments:

recurFunc	Recursive Function, the the array of last values will be passed as first arg, count as second arg.
length	Number of output items, may be pattern or stream, defaults to inf.
bufSize	Size of buffer to store last values. If bufSize is not defined and start is not given or a single item, bufSize gets value 1. If bufSize is not defined and start is an array bufSize gets its length.
start	Single start item or array of items used for recursion.
copyItems	Determines if and how to copy the last items generated by recurFunc which are either non-Sets or member of Sets. Takes Integer 0 (or false or Symbol \false), 1 (or true or Symbol \true) or 2 (or Symbol \deep). Other values are interpreted as 0. Defaults to 0. 0: original item 1: copy item 2: deepCopy item
copySets	Determines if and how to copy Sets generated by recurFunc. Takes Integer 0 (or false or Symbol \false), 1 (or true or Symbol \true). Other values are interpreted as 0. Defaults to 1. 0: original Set 1: copy Set NOTE: The distinction of copying items and sets makes sense in the case of event streams. Per default Events are copied (copySets == 1), not their values (copyItems == 0). By playing Events those are used to store additional data (synth ids, msgFuncs …) which is mostly not of interest when refering to the event stream, e.g. with PSx patterns which use MemoRoutine - copied Events will not contain this additional data. If values of Events or values returned directly by the stream (being no kind of Sets) are unstructured then copying makes no sense, this is the normal case, so copyItems defaults to 0. When going to alter the ouput, you might want to set copyItems to 1 for a PSx returning simple arrays or 2 for nested arrays (deepCopy). For deepCopying Events you'd have to set copySets to 1 and copyItems to 2 (an option copySets == 2 doesn't exist as it would be contradictory in combination with copyItems < 2). NOTE: Copy options concern copying into PSrecur's buffer as well as the output of a Stream derived from the PSrecur. When such a Stream is outputting copies this prevents unintended altering of items stored in the buffer of PSrecur. On the other hand storing copies in PSrecur's buffer prevents these from being altered unintendedly.

Instance Methods

.recurFuncStream

Instance variable getter and setter methods.

Examples

(
s = Server.local;
Server.default = s;
s.boot;
)

// another way to generate the fibonacci sequence
// the first arg passed to the Function is the PSrecur itself,
// x[0] refers to its last value, x[1] to the value before the last value

(
a = PSrecur({ |x| x[0] + x[1] }, start: [0, 1]);
b = a.iter;
b.nextN(10);
)

// shorter with partial application

PSrecur(_[0]+_[1], start: [0, 1]).iter.nextN(10);

// recursion with event patterns
// function calculates an iterated average of past event values for all keys,
// events at the end of the array are taken into account most.

(
u = { |e,f| e.copy.keysValuesChange { |k| e[k]+f[k]/2 } };
v = { |a| a.reduce(u) };
)

(
// three basic Events

e = (midinote: 65, dur: 0.75, amp: 0.1, pan: 0);
f = (midinote: 58, dur: 0.05, amp: 0.3, pan: -1);
g = (midinote: 92, dur: 0.05, amp: 0.4, pan: 1);

// mostly build "blurred" average of last five events,
// by chance disturbance by choosing a basic event

p = PSrecur({ |x| 0.8.coin.if { v.(x[..4]) }{ [e,f,f,g].choose } }, start: [e,f,e,g,e]);

q = p.trace.play;
)

q.stop;

helpfile source: HelpSource/Classes/PSrecur.schelp
link::miSCellaneous_lib/Classes/PSrecur::

PSrecurExtension