creating a stringHarmonic function

[Kieren MacMillan]

> Top posting is often superior to bottom-posting.

[Sorry... the web email interface I'm forced to use while my MacBook is in for
repairs clearly messed up the last post, so I'm forced to used gmane.  =\]

Hello, all!

I'm trying to come up with a Scheme function to generate string harmonics
automatically.

I figured I'd do it in two steps:
1. Create a function that takes a chord of three notes, and formats each
note(head) appropriately.
2. Modify the function to take one or two notes, and generate the other parts of
the notation accordingly/conditionally.

I've started Phase 1 by trying to see how I would build it manually:
____________________________

\version "2.12.2"

originalMusic =
{
  <c' f' c'''>1
  <c' f' c'''>8
}

harmonicMusic =
{
  \once \override ParenthesesItem #'font-size = #-1
  <c' f'\harmonic
    \tweak #'font-size #-2
    \tweak #'duration-log #4
    \parenthesize
      c'''
>1

\once \override ParenthesesItem #'font-size = #-1
<c' f'\harmonic
  \tweak #'font-size #-2
  \tweak #'duration-log #4
  \parenthesize
    c'''
>8
}

\displayMusic { \originalMusic }
\displayMusic { \harmonicMusic }

____________________________

Questions:
1. Is this a good way to go about formatting the note(head)s?
2. Is #'duration-log the best way to force the sounding pitch to look like a
quarter-note head, regardless of the chord's native duration? [Obviously the
sounding pitch adjustment should have no effect on the timing of the chord.]
3. How can I turn off the stem of the sounding pitch? [n.b. I know I could put
it in a separate Voice context, but I'd like to avoid that if possible.]

Thanks!
Kieren.