Description

Beta distribution random number generator (positive values only). This is an x-class noise generator.

Syntax

ares betarand krange, kalpha, kbeta

ires betarand krange, kalpha, kbeta

kres betarand krange, kalpha, kbeta

Performance

krange -- range of the random numbers (0 - krange).

kalpha -- alpha value. If kalpha is smaller than one, smaller values favor values near 0.

kbeta -- beta value. If kbeta is smaller than one, smaller values favor values near krange.

If both kalpha and kbeta equal one we have uniform distribution. If both kalpha and kbeta are greater than one we have a sort of Gaussian distribution. Outputs only positive numbers.

For more detailed explanation of these distributions, see:

Examples

Here is an example of the betarand opcode. It uses the file betarand.csd.

<CsoundSynthesizer>
<CsOptions>
; Select audio/midi flags here according to platform
; Audio out   Audio in
-odac           -iadc    ;;;RT audio I/O
; For Non-realtime ouput leave only the line below:
; -o betarand.wav -W ;;; for file output any platform
</CsOptions>
<CsInstruments>

; Initialize the global variables.
sr = 44100
kr = 4410
ksmps = 10
nchnls = 1

; Instrument #1.
instr 1
  ; Generate a number between 0 and 1 with a 
  ; uniform distribution.
  ; krange = 1
  ; kalpha = 1
  ; kbeta = 1

  i1 betarand 1, 1, 1

  print i1
endin


</CsInstruments>
<CsScore>

; Play Instrument #1 for one second.
i 1 0 1
e


</CsScore>
</CsoundSynthesizer>

Its output should include a line like:

instr 1:  i1 = 24583.412
      

See Also

seed, bexprnd, cauchy, exprand, gauss, linrand, pcauchy, poisson, trirand, unirand, weibull

Credits

Existed in 3.30

Example written by Kevin Conder.