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phasorbnk

Produce an arbitrary number of normalized moving phase values, accessable by an index.

Syntax

ares = phasorbnk(xcps, kndx, icnt [, iphs])
kres = phasorbnk(kcps, kndx, icnt [, iphs])

ares phasorbnk xcps, kndx, icnt [, iphs]
kres phasorbnk kcps, kndx, icnt [, iphs]

Initialization

icnt -- maximum number of phasors to be used.

iphs -- initial phase, expressed as a fraction of a cycle (0 to 1). If -1 initialization is skipped. If iphas>1 each phasor will be initialized with a random value.

Performance

kndx -- index value to access individual phasors

For each independent phasor, an internal phase is successively accumulated in accordance with the kcps or xcps frequency to produce a moving phase value, normalized to lie in the range 0 <= phs < 1. Each individual phasor is accessed by index kndx.

This phasor bank can be used inside a k-rate loop to generate multiple independent voices, or together with the adsynt opcode to change parameters in the tables used by adsynt.

Examples

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

Example of the phasorbnk opcode.
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<CsoundSynthesizer>
<CsOptions>
; Select audio/midi flags here according to platform
; Audio out   Audio in    No messages
-odac           -iadc     -d     ;;;RT audio I/O
; For Non-realtime ouput leave only the line below:
; -o phasorbnk.wav -W ;;; for file output any platform
</CsOptions>
<CsInstruments>

; Initialize the global variables.
sr = 44100
kr = 4410
ksmps = 10
nchnls = 1

; Generate a sinewave table.
giwave ftgen 1, 0, 1024, 10, 1 

; Instrument #1
instr 1
  ; Generate 10 voices.
  icnt = 10 
  ; Empty the output buffer.
  asum = 0 
  ; Reset the loop index.
  kindex = 0 

; This loop is executed every k-cycle.
loop: 
  ; Generate non-harmonic partials.
  kcps = (kindex+1)*100+30 
  ; Get the phase for each voice.
  aphas phasorbnk kcps, kindex, icnt 
  ; Read the wave from the table.
  asig table aphas, giwave, 1 
  ; Accumulate the audio output.
  asum = asum + asig 

  ; Increment the index.
  kindex = kindex + 1

  ; Perform the loop until the index (kindex) reaches 
  ; the counter value (icnt).
  if (kindex < icnt) kgoto loop 

  out asum*3000
endin


</CsInstruments>
<CsScore>

; Play Instrument #1 for two seconds.
i 1 0 2
e


</CsScore>
</CsoundSynthesizer>

Generate multiple voices with independent partials. This example is better with adsynt. See also the example under adsynt, for k-rate use of phasorbnk.

See also

Phasors

Credits

Author: Peter Neubäcker
Munich, Germany
August 1999

New in Csound version 3.58