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cossegb

Trace a series of line segments between specified absolute points with cosine interpolation.

Syntax

ares = cossegb(ia, itim1, ib [, itim2] [, ic] [...])
kres = cossegb(ia, itim1, ib [, itim2] [, ic] [...])

ares cossegb ia, itim1, ib [, itim2] [, ic] [...]
kres cossegb ia, itim1, ib [, itim2] [, ic] [...]

Initialization

ia -- starting value.

ib, ic, etc. -- value at tim1 seconds, etc.

itim1 -- time in seconds of end of first segment. A zero or negative value will cause all initialization to be skipped.

itim2, itim3, etc. -- time in seconds at the end of subsequent segments. Give times in increasing order. Equal times cause an immediate jump to the next value.

Performance

Times use whole samples at audio rate and whole control periods at control rate. Breakpoints that fall on the same output step cause an immediate jump; later segments still run.

These units generate control or audio signals whose values can pass through 2 or more specified points. The last tim value 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 value to be repeated until the end of the note.

Examples

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

Example of the cossegb opcode.
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<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 linseg.wav -W ;;; for file output any platform
</CsOptions>
<CsInstruments>

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

giSine ftgen 0, 0, 2^10, 10, 1

instr 1

kcps = cpspch(p4)
kenv cossegb 0, 0.25, 1, 1, 0
asig poscil kenv, kcps, giSine
     outs asig, asig

endin

instr 2 ; scaling to duration

kcps = cpspch(p4)
kenv cossegb 0, p3*0.25, 1, p3, 0
asig poscil kenv, kcps, giSine
     outs asig, asig

endin

</CsInstruments>
<CsScore>

i 1 0 1   7.00  ; = 1 sec, p3 fits exactly
i 1 2 2   7.00  ; = 2 sec, p3 truncated at 1 sec

i 2 4 1   7.00  ; scales to duration
i 2 6 2   7.00  ; of p3

e
</CsScore>
</CsoundSynthesizer>

See also

Linear and Exponential Generators

Credits

Author: John ffitch
Aug 2012

New in version 5.18