expsega

An exponential segment generator operating at a-rate.

This unit is almost identical to expseg, but more precise when defining segments with very short durations (i.e., in a percussive attack phase) at audio rate.

Syntax

ares expsega ia, idur1, ib [, idur2] [, ic] [...]

Initialization

ia -- starting value. Zero is illegal.

ib, ic, etc. -- value after idur1 seconds, etc. 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.

Performance

This unit generate audio signals whose values can pass through two 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.

Examples

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

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

; by Kevin Conder, Menno Knevel 2021

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

instr 1

aenv expsega 0.01, 0.1, 1, 0.1, 0.01    ; Define a short percussive amplitude envelope
a1   oscili aenv, 440
     outs a1, a1

endin

</CsInstruments>
<CsScore>
i 1 0 1
i 1 1 1
i 1 2 1
i 1 3 3
e
</CsScore>
</CsoundSynthesizer>

See also

Linear and Exponential Generators

Credits

Author: Gabriel Maldonado

New in Csound 3.57