#lang scribble/manual
@(require (for-label racket))

@title{TWindex}
 Triggered windex.@section{categories}
  UGens>Random, UGens>Triggers


@section{description}


When triggered, returns a random index value based on array as a list of
probabilities. By default the list of probabilities should sum to 1.0,
when the normalize flag is set to 1, the values get normalized
by the UGen (less efficient).


@section{classmethods}
 

@section{method}
 ar, kr

@section{argument}
 in

The trigger. Trigger can be any signal. A trigger happens when
the signal changes from non-positive to positive.


@section{argument}
 array
The list of probabilities.

@section{argument}
 normalize
Controls whether to normalize the probability values.

@section{Examples}
 


@racketblock[

//assuming normalized values
(

a = SynthDef("help-TWindex",{ arg w1=0.0, w2=0.5, w3=0.5;

	var trig, index;
	trig = Impulse.kr(6);
	index = TWindex.kr(trig, [w1, w2, w3]);

	Out.ar(0,
		SinOsc.ar(
			Select.kr(index,[400, 500, 600]),
			0, 0.2
		)
	)
}).play;

)

a.setn(0, [0,0,1].normalizeSum);
a.setn(0, [1,1,1].normalizeSum);
a.setn(0, [1,0,1].normalizeSum);


//modulating probability values
(

a = SynthDef("help-TWindex",{ arg w1=0.0, w2=0.5;

	var trig, index;
	trig = Impulse.kr(6);
	index = TWindex.kr(
					trig,
					[w1, w2, SinOsc.kr(0.3, 0, 0.5, 0.5)],//modulate probability
					1 //do normalisation
		);

	Out.ar(0,
		SinOsc.ar(
			Select.kr(index,[400, 500, 600]),
			0, 0.2
		)
	)
}).play;

)

a.setn(0, [0,0]);
a.setn(0, [1,1]);
a.setn(0, [1,0]);
a.setn(0, [0,1]);

::
]