| f2st {hqmisc} | R Documentation |
Convert between frequency in Hz and in semitones
Description
Convert between frequency in Hz and in semitones, relative to baseline frequency in Hz.
Usage
f2st( hz, base=50 )
st2f( st, base=50 )
Arguments
hz |
a frequency in Hertz (cycles per second). |
st |
a frequency in semitones relative to the base frequency. |
base |
the baseline frequency (in Hertz units) relative to which semitones are expressed. |
Details
These functions convert between the linear Hertz and logarithmic semitone scales. A doubling of the frequency in Hz equals 12 semitones or 1 octave.
Function f2st was based on function h2st by Mark Liberman
(last seen at http://ldc.upenn.edu/myl/llog/semitones.R but no longer available online).
Function st2f was based on a conversion script by Jan Roelof de Pijper
(last seen at http://users.abo.fi/jtuomain/speech/semitone.html but no longer available online).
For frequencies in Hz of musical notes, see e.g. http://www.phy.mtu.edu/~suits/notefreqs.html.
Value
Transformed value(s) in semitones or in Hertz (cycles per second).
See Also
Examples
# distance in semitones between target and baseline frequencies in Hz.
f2st( 440, base=110 )
# frequency in Hz of a tone that is +24 semitones distant
# from the baseline, i.e. a distance of +two octaves.
st2f( 24 )