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trirand

Triangular distribution random number generator

This is an x-class noise generator.

Syntax

ares trirand krange
ires trirand krange
kres trirand 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 trirand opcode. It uses the file trirand.csd.

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

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

instr 1         ; every run time same values

ktri    trirand 100
        printk .2, ktri                 ; look 
aout    oscili 0.8, 440+ktri, 1         ; & listen
        outs    aout, aout
endin

instr 2         ; every run time different values

        seed 0
ktri    trirand 100
        printk .2, ktri                 ; look 
aout    oscili 0.8, 440+ktri, 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     0.00067:    -4.97993
i   1 time     0.20067:     1.20909
i   1 time     0.40067:    17.45873
i   1 time     0.60067:    52.55409
i   1 time     0.80067:    -1.92888
i   1 time     1.00000:   -11.01149
i   1 time     1.20067:     9.79521
i   1 time     1.40067:    26.98504
i   1 time     1.60067:    24.67405
i   1 time     1.80000:   -67.59846
i   1 time     2.00000:    64.24861
WARNING: Seeding from current time 521999639
i   2 time     3.00067:     3.28969
i   2 time     3.20067:    54.98986
i   2 time     3.40067:   -33.84788
i   2 time     3.60000:   -41.93523
i   2 time     3.80067:    -6.61742
i   2 time     4.00000:    39.67097
i   2 time     4.20000:     2.95123
i   2 time     4.40067:    45.59255
i   2 time     4.60067:    16.57259
i   2 time     4.80067:   -18.80273
i   2 time     5.00000:    -2.01697

See also

Random (Noise) Generators

Credits

Author: Paris Smaragdis
MIT, Cambridge
1995