wgbowedbar

Name

wgbowedbar --  A physical model of a bowed bar.

Description

A physical model of a bowed bar, belonging to the Perry Cook family of waveguide instruments.

Syntax

ar wgbowedbar kamp, kfreq, kpos, kbowpres, kgain [, iconst] [, itvel] [, ibowpos] [, ilow]

Initialization

iconst (optional, default=0) -- an integration constant. Default is zero.

itvel (optional, default=0) -- either 0 or 1. When ktvel = 0, the bow velocity follows an ADSR style trajectory. When ktvel = 1, the value of the bow velocity decays in an exponentially.

ibowpos (optional, default=0) -- the position on the bow, which affects the bow velocity trajectory.

ilow (optional, default=0) -- lowest frequency required

Performance

kamp -- amplitude of signal

kfreq -- frequency of signal

kpos -- position of the bow on the bar, in the range 0 to 1

kbowpres -- pressure of the bow (as in wgbowed)

kgain -- gain of filter. A value of about 0.809 is suggested.

Examples

Here is an example of the wgbowedbar opcode. It uses the files wgbowedbar.orc and wgbowedbar.sco.

Example 15-1. Example of the wgbowedbar opcode.

/* wgbowedbar.orc */
; Initialize the global variables.
sr = 44100
kr = 4410
ksmps = 10
nchnls = 1

  instr 1
; pos      =         [0, 1]
; bowpress =         [1, 10]
; gain     =         [0.8, 1]
; intr     =         [0,1]
; trackvel =         [0, 1]
; bowpos   =         [0, 1]

  kb      line 0.5, p3, 0.1
  kp      line 0.6, p3, 0.7
  kc      line 1, p3, 1

  a1      wgbowedbar p4, cpspch(p5), kb, kp, 0.995, p6, 0

          out a1
          endin
/* wgbowedbar.orc */
        
/* wgbowedbar.sco */
  i1      0  3 32000 7.00 0
  e
/* wgbowedbar.sco */
        

Credits

Author: John ffitch (after Perry Cook)
University of Bath, Codemist Ltd.
Bath, UK

New in Csound version 4.07