I fixed up the n2p routine, although not in the same output format as the book
(“Cybernetic Music”) it seems to track the relative octave increases and
decreases from the examples. I apologize for the not very J-ish style for the
support routine ‘ROCT’ (new routine not part of the original APL).
NB. ROCT - relative octave processing. The goal is to move down
NB. a list of note numbers and record upticks and down tics in
NB. octave.
NB. x is the starting relative octave (usually 0)
NB. y is the array of notes
ROCT =: 4 : 0
aoct =. <.y%TONSYS
smoutput aoct
loct =. x
oct =. 1$loct
for_i. aoct do.
delta =. i - loct
oct =. oct, i - loct
if. delta ~: 0 do.
loct =. i
end.
end.
oct
)
NB. N2P - in J using boxing to generate and display pitch names
NB. this makes it much easier to manipulate than the APL
NB. routines originally developed
n2p =: 3 : 0
NB. Octave would be the relative octave away from main octave
NB. The octave is found by dividing by the # of tones in an octave
NB. ie. divide by TONSYS and then using floor <. to produce the
NB. integer truncation. Then use format ": to turn it all into
NB. Text
octave =. ": each ;/ }. 0 ROCT y
NB. The following will map a note to it's text pitch name
pitch =. (TONSYS|y) { _3 <\NOTENAME
(('0';' ')&stringreplace each octave),:pitch
)
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