The Alternative Csound Reference Manual
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# octave

octave -- Calculates a factor to raise/lower a frequency by a given amount of octaves.

## Description

Calculates a factor to raise/lower a frequency by a given amount of octaves.

## Syntax

octave(x)

This function works at a-rate, i-rate, and k-rate.

## Initialization

x -- a value expressed in octaves.

## Performance

The value returned by the octave function is a factor. You can multiply a frequency by this factor to raise/lower it by the given amount of octaves.

## Examples

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

Example 1. Example of the octave opcode.

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

    ; Instrument #1.
    instr 1
      ; The root note is A above middle-C (440 Hz)
      iroot = 440

      ; Raise the root note by two octaves.
      ioctaves = 2

      ; Calculate the new note.
      ifactor = octave(ioctaves)
      inew = iroot * ifactor

      ; Print out of all of the values.
      print iroot
      print ifactor
      print inew
    endin
    /* octave.orc */

    /* octave.sco */
    ; Play Instrument #1 for one second.
    i 1 0 1
    e
    /* octave.sco */

Its output should include lines like:

    instr 1:  iroot = 440.000
    instr 1:  ifactor = 4.000
    instr 1:  inew = 1760.149

## See Also

cent, db, semitone

## Credits

Example written by Kevin Conder.

New in version 4.16

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