On Sun, Oct 12, 2014 at 5:59 PM, Hans Sommer <hansisom...@gmx.de> wrote:
>
> David Nalesnik <david.nalesnik <at> gmail.com> writes:
>
> >
> > Hi Hans,
> > On Sun, Oct 12, 2014 at 4:38 AM, Hans Sommer <hansisommer <at> gmx.de>
> wrote:Hello,
> > I am relatively new to Lilypond.
> > I try to check the total length of a SequentialMusic part, i.e.
> > my_score_part = { c'4 d e f }
> > I want to get the result 4 quarters (or any other numerical
> representation)
> > and for
> > my_score_part2 = { c'4 d e f g8}
> >
> >
> > (This isn't a valid name for a variable, so I changed it below.)
> >
> >
> >
> > should deliver 4 quarter and 1 eighth.
> > I found in the documentation the property:
> > length-callback (procedure):
> > ly:music-sequence::cumulative-length-callback
> > but I don't know how to use it.
> > I would be very thankful, if anybody could provide an example.
> >
> >
> > I'm not familiar with this property, but it's relatively easy to
> determine
> the length of a music expression. Try this:
> >
> > \version "2.19.10"
> >
> > my_score_part = { c'4 d e f }
> >
> > my_score_part_two = { c'4 d e f g8 }
> >
> > #(display (ly:music-length my_score_part))
> >
> > #(display (ly:music-length my_score_part_two))
> >
> > Hope this is helpful,
> > David
> >
> >
> >
> >
> >
> > _______________________________________________
> > lilypond-user mailing list
> > lilypond-user <at> gnu.org
> > https://lists.gnu.org/mailman/listinfo/lilypond-user
> >
>
> Thank you David,
>
> that was what I was looking for.
>
> When I use
> #(display (ly:music-length my_score_part))
> I get in the lilypond log file (depending on the score length) someting
> like
> that:
>
> #<Mom 2>
>
> Is there a possibility to write the result in an extra text file (I want
> to
> process the result by a program, that is actually starting the lilypond
> compilation. It should check the score length and eventually throw an
> error).
>
Yes, you can specify a port for display:
\version "2.19.10"
my_score_part = { c'4 d e f }
my_score_part_two = { c'4 d e f g8 }
#(define out (open-output-file "music-length.txt"))
#(display (ly:music-length my_score_part) out)
#(display (ly:music-length my_score_part_two) out)
%%%
You could also use format for nicer output:
#(format out "Length of my_score_part: ~a~%Length of my_score_part_two:
~a~%"
(ly:music-length my_score_part)
(ly:music-length my_score_part_two))
%%%
I don't think you need to close the port, but you could add this:
#(close-output-port out)
--David
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