an open-source digital signal processing and sound synthesis language
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cpslet - convert text-string note letter representation to frequency (Hz)


Synopsis

freq = cpslet("lettername")


Description

cpslet returns a corresponding frequency value (Hz) for a text-string note letter representation. In this 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, cpslet will return the value for middle C (261.625565301 Hz).

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])


Arguments

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


Examples

   freq = cpslet("F2")
   freq = cpslet("A#5")

See Also

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