expseg — Trace a series of exponential segments between specified points.


Trace a series of exponential segments between specified points.


ares expseg ia, idur1, ib [, idur2] [, ic] [...]
kres expseg ia, idur1, ib [, idur2] [, ic] [...]


ia -- starting value. Zero is illegal for exponentials.

ib, ic, etc. -- value after dur1 seconds, etc. For exponentials, must be non-zero and must agree in sign with ia.

idur1 -- duration in seconds of first segment. A zero or negative value will cause all initialization to be skipped.

idur2, idur3, etc. -- duration in seconds of subsequent segments. A zero or negative value will terminate the initialization process with the preceding point, permitting the last-defined line or curve to be continued indefinitely in performance. The default is zero.


These units generate control or audio signals whose values can pass through 2 or more specified points. The sum of dur values may or may not equal the instrument's performance time: a shorter performance will truncate the specified pattern, while a longer one will cause the last-defined segment to continue on in the same direction.

Note that the expseg opcode does not operate correctly at audio rate when segments are shorter than a k-period. Try the expsega opcode instead.


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

Example 284. Example of the expseg opcode.

See the sections Real-time Audio and Command Line Flags for more information on using command line flags.

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

; by Kevin Conder, additions by Menno Knevel 2021

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

instr 1
kcps = cpspch(p4)                           ; p4 = frequency in pitch-class notation.
kenv expseg 0.01, p3*0.25, 1, p3*0.75, 0.001 ; amplitude envelope.
kamp = kenv 
a1 oscili kamp, kcps
outs a1, a1



i 1 0 0.5 8.00
i 1 1 0.5 8.01
i 1 2 0.5 8.02
i 1 3 2.0 8.03

See also

Linear and Exponential Generators


Author: Gabriel Maldonado

New in Csound 3.57