The subroutines glkern.f and lokern.f use an efficient and fast algorithm for
automatically adaptive nonparametric regression estimation with a kernel method.
Roughly speaking, the method performs a local averaging of the observations when
estimating the regression function. Analogously, one can estimate derivatives of
small order of the regression function.
Frequency Scale Conversion
From f To f Scale
frq2mel mel2frq mel The mel scale is based on the human perception of sinewave pitch.
frq2erb erb2frq erb The erb scale is based on the equivalent rectangular bandwidths of the human ear.
frq2midi midi2frq midi The midi standard specifies a numbering of semitones with middle C being 60. They can use the normal equal tempered scale or else the pythagorean scale of just intonation. They will in addition output note names in a character format.