an open-source digital signal processing and sound synthesis language
about · links · contact
octlet - convert text-string note letter representation to linear octaves


linoct = octlet("lettername")


octlet returns a corresponding linear octave value for a text-string note letter representation. Linear octaves are similar to octave.pitch-class (oct.pc) notation in that 8.00 is middle C, 9.00 is the C an octave above, etc. The difference is that the fractional part of the specification represents a direct mapping onto the notes of the scale between octaves. For example, in oct.pc notation the value 8.06 represents F-sharp (the tritone, 1/2 the chromatic scale between 8.00 and 9.00). This would be represented as 8.5 in linear octaves.

In text-string note letter representation, the note letter-name is given with a capital letter ("A", "B", "C", etc.) followed by an optional "#" (sharp) or "b" (flat) modifier, and then an octave-specifier (octave "4" is middle C). See pitch-reps for more information about this method of represetation.

If the pitch-specification is invalid or malformed, octlet will return the value for middle C (8.00).

NOTE: With the exception of boost, The RTcmix conversion functions follow a pattern. The command isdivided into two halves, the one closest to the argument represent the format of the argument, and the one closest to the assignment represents the format to be returned. For example, "cpspch" is divided into "cps" and "pch". The argument is in oct.pc form ("pch") and the return value will be in cps ("cps").

The various format specifiers are:

   amp = absolute amplitude (16-bit, 0-32768)
   cps = cycles per second (Hz)
   db = decibels
   midi = midi note # (60 is middle C)
   oct = linear octaves (8.5 is halfway between octave 8.00 [middle C] and 9.00)
   pch = octave.pitch-class (oct.pc; 8.00 is middle C, 8.02 is D, 8.12 = 9.00 = C above middle C)
   let = note-letter specification ("C4" is middle C, "C#4" is C-sharp above middle C,
      "Gb5" is G-flat the octave above middle C octave. [again, see pitch-reps for more info])


A text-string representing a valid note name (see above)


   loct = octlet("G8")
   loct = octlet("Bb3")

See Also

ampdb, boost, dbamp, cpslet, cpsmidi, cpsoct, cpspch, midipch, octcps, octmidi, octpch, pchcps, pchlet, pchmidi, pchoct