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bexprnd

Exponential distribution random number generator.

This is an x-class noise generator.

Syntax

ares bexprnd krange
ires bexprnd krange
kres bexprnd krange

Performance

krange -- the range of the random numbers (-krange to +krange)

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 bexprnd opcode. It uses the file bexprnd.csd.

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

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

instr 1         ; every run time same values

kexp    bexprnd 100
        printk .2, kexp                 ; look 
aout    oscili 0.8, 440+kexp, 1         ; & listen
        outs    aout, aout

endin

instr 2         ; every run time different values

        seed 0
kexp    bexprnd 100
        printk .2, kexp                 ; look 
aout    oscili 0.8, 440+kexp, 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:

i   1 time     0.00267:    99.27598
i   1 time     0.20267:    74.97176
i   1 time     0.40267:   -35.67213
i   1 time     0.60267:     1.10579
i   1 time     0.80267:   -18.08816
i   1 time     1.00000:    28.93329
i   1 time     1.20267:   320.63733
i   1 time     1.40267:  -332.05614
i   1 time     1.60267:  -212.66361
i   1 time     1.80000:   -92.57433
i   1 time     2.00000:   140.70939
Seeding from current time 4055201702
i   2 time     3.00267:   190.30495
i   2 time     3.20267:   -58.30677
i   2 time     3.40267:   192.39784
i   2 time     3.60000:    12.72448
i   2 time     3.80267:    79.91503
i   2 time     4.00000:    34.44258
i   2 time     4.20000:   167.92680
i   2 time     4.40267:  -117.10278
i   2 time     4.60267:   -70.99155
i   2 time     4.80267:   -23.24037
i   2 time     5.00000:  -226.35500

See also

Random (Noise) Generators

Credits

Author: Paris Smaragdis
MIT, Cambridge
1995