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pcauchy

Cauchy distribution random number generator (positive values only).

This is an x-class noise generator.

Syntax

ares pcauchy kalpha
ires pcauchy kalpha
kres pcauchy kalpha

Performance

pcauchy kalpha -- controls the spread from zero (big kalpha = big spread). Outputs positive numbers only.

For more detailed explanation of these distributions, see:

  1. C. Dodge - T.A. Jerse 1985. Computer music. Schirmer books. pp.265 - 286
  2. D. Lorrain. A panoply of stochastic cannons. In C. Roads, ed. 1989. Music machine. Cambridge, Massachusetts: MIT press, pp. 351 - 379.

Examples

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

Example of the pcauchy opcode.
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<CsoundSynthesizer>
<CsOptions>
; Select audio/midi flags here according to platform
-odac     ;;;realtime audio out
;-iadc    ;;;uncomment -iadc if real audio input is needed too
; For Non-realtime ouput leave only the line below:
; -o pcauchy.wav -W ;;; for file output any platform
</CsOptions>
<CsInstruments>

sr = 44100
ksmps = 32
nchnls = 2
0dbfs  = 1

instr 1         ; every run time same values

kalpha  pcauchy 1000
        printk  .2, kalpha              ; look
aout    oscili  0.8, 440+kalpha, 1      ; & listen
        outs    aout, aout
endin

instr 2         ; every run time different values

        seed 0
kalpha  pcauchy 1000
        printk  .2, kalpha              ; look 
aout    oscili  0.8, 440+kalpha, 1      ; & listen
        outs    aout, aout
endin
</CsInstruments>
<CsScore>
; sine wave
f 1 0 16384 10 1

i 1 0 2
i 2 3 2
e

</CsScore>
</CsoundSynthesizer>

Its output should include a line like this:

i   1 time     0.00033:    10.48851
i   1 time     0.20033:     0.29508
i   1 time     0.40033:     1.75214
i   1 time     0.60033:    22.88281
i   1 time     0.80033:    16.06435
i   1 time     1.00000:     0.43110
i   1 time     1.20033:    16.51694
i   1 time     1.40033:     2.98797
i   1 time     1.60033:     1.32767
i   1 time     1.80000:    17.94039
i   1 time     2.00000:     4.85994
Seeding from current time 1526147515
i   2 time     3.00033:     0.89797
i   2 time     3.20033:     9.19447
i   2 time     3.40033:     0.73053
i   2 time     3.60000:     7.43371
i   2 time     3.80033:     5.87640
i   2 time     4.00000:     0.80456
i   2 time     4.20000:     4.50637
i   2 time     4.40033:     2.08145
i   2 time     4.60033:    13.47125
i   2 time     4.80033:     3.16399
i   2 time     5.00000:    11.05428

See also

Random (Noise) Generators

Credits

Author: Paris Smaragdis
MIT, Cambridge
1995