randomh

Generates random numbers with a user-defined limit and holds them for a period of time.

Syntax

ares randomh kmin, kmax, xcps [,imode] [,ifirstval]
kres randomh kmin, kmax, kcps [,imode] [,ifirstval]

Initialization

imode (optional, default=0) -- generation mode of the first output value (see below)

ifirstval (optional, default=0) -- first output value

Performance

kmin -- minimum range limit

kmax -- maximum range limit

kcps, xcps -- rate of random break-point generation

The randomh opcode is similar to randh but allows the user to set arbitrary minimum and maximum values.

When imode = 0 (the default), the kmin argument value is outputted during 1/kcps (resp. 1/xcps) seconds at the beginning of the note. Then, the normal process takes place with a new random number generated and held every 1/kcps (resp. 1/xcps) seconds.

When imode = 2, the ifirstval argument value is outputted during 1/kcps (resp. 1/xcps) seconds at the beginning of the note. Then, the normal process takes place with a new random number generated and held every 1/kcps (resp. 1/xcps) seconds.

When imode = 3, the generation process begins with a random value from the initialization time.

Examples

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

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

; by Kevin Conder & Menno Knevel, adapted for new args by Francois Pinot.

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

seed 0

instr 1

kmin    init 220; Choose a random frequency between 220 and 440 Hz.
kmax    init 440
kcps    init 10; Generate new random numbers at 10 Hz.
imode   =    p4
ifstval =    p5

printf_i "\nMode: %d\n", 1, imode
k1 randomh kmin, kmax, kcps, imode, ifstval
printk2 k1
asig    poscil  1, k1
outs    asig, asig
endin

</CsInstruments>
<CsScore>
; each time with a different mode.
i 1 0 1
i 1 2 1 2 330
i 1 4 1 3
e
</CsScore>
</CsoundSynthesizer>

Its output should include lines like this:

Mode: 0
i1   220.00000
i1   396.26079
i1   240.75446
i1   364.24577
...

Mode: 2
i1   330.00000
i1   416.50935
i1   356.11619
i1   433.59324
...

Mode: 3
i1   261.17741
i1   402.00891
i1   393.86592
i1   307.19839
...

Two musical examples featuring the randomh opcode: FtmorfRandomh_Cucchi.csd and Ftmorf_Cucchi.csd, both by Stefano Cucchi.

See also

Random (Noise) Generators

Credits

Author: Gabriel Maldonado

Arguments imode and ifirstval added by François Pinot, Jan. 2011, after a discussion with Peiman Khosravi on the csnd list.