urd — A discrete user-defined-distribution random generator that can be used as a function.
itableNum -- number of table containing the random-distribution function. Such table is generated by the user. See GEN40, GEN41, and GEN42. The table length does not need to be a power of 2
ktableNum -- number of table containing the random-distribution function. Such table is generated by the user. See GEN40, GEN41, and GEN42. The table length does not need to be a power of 2
urd is the same opcode as duserrnd, but can be used in function fashion.
For a tutorial about random distribution histograms and functions see:
D. Lorrain. "A panoply of stochastic cannons". In C. Roads, ed. 1989. Music machine. Cambridge, Massachusetts: MIT press, pp. 351 - 379.
Here is an example of the urd opcode. It uses the file urd.csd.
Example 1142. Example of the urd opcode.
See the sections Real-time Audio and Command Line Flags for more information on using command line flags.
<CsoundSynthesizer> <CsOptions> ; Select audio/midi flags here according to platform -odac ;;;realtime audio out ;-iadc ;;;uncomment -iadc if realtime audio input is needed too ; For Non-realtime ouput leave only the line below: ; -o urd.wav -W ;;; for file output any platform </CsOptions> <CsInstruments> sr = 44100 ksmps = 32 nchnls = 2 0dbfs = 1 instr 1 ktab = 1 ;ftable 1 kurd = urd(ktab) ktrig metro 5 ;triggers 5 times per second kres samphold kurd, ktrig ;sample and hold value of kurd printk2 kres ;print it asig poscil .5, 220+kres, 2 outs asig, asig endin instr 2 seed 0 ;every run new values ktab = 1 ;ftable 1 kurd = urd(ktab) ktrig metro 5 ;triggers 5 times per second kres samphold kurd, ktrig ;sample and hold value of kurd printk2 kres ;print it asig poscil .5, 220+kres, 2 outs asig, asig endin </CsInstruments> <CsScore> f1 0 -20 -42 10 20 .3 100 200 .7 ;30% choose between 10 and 20 and 70% between 100 and 200 f2 0 8192 10 1 ;sine wave i 1 0 5 i 2 6 5 e </CsScore> </CsoundSynthesizer>
Its output should include lines like these:
i1 184.61538
i1 130.76923
i1 169.23077
i1 12.00000
.......
WARNING: Seeding from current time 3751086165
i2 138.46154
i2 12.00000
i2 123.07692
i2 161.53846
i2 123.07692
i2 153.84615
......