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Re: Problem with scaled durations
From: |
David Kastrup |
Subject: |
Re: Problem with scaled durations |
Date: |
Thu, 03 Jan 2013 00:42:53 +0100 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/24.3.50 (gnu/linux) |
Oscar Dub <address@hidden> writes:
> Hi everyone,
>
> There appears to be an issue with long lists of differently scaled LilyPond
> notes where they fail to display, but leave no trace of a problem in the log
> (example below). I'm having difficulty condensing the issue into something
> simple enough to send to the bug list, but maybe someone with more insight
> into how LilyPond calculates time intervals internally can help out.
>
> I thought the problem had something to do with using too many different
> denominators in the fractions used by the scale syntax. To test this idea
> out, I made a script generating notes scaled by multipliers from 1/1 to 1/n
> (output for n=30 shown below).
>
> Running my file, LilyPond only manages to render up to note 18.
You calculate 1/4*(1 + 1/2 + 1/3 + 1/4 ... + 1/18)
If we take a look at the result, it is 14274301:16336320. Now
multiplying with 1/(4*19) gives 751279:65345280 and the intermediate
calculation has a denominator of 1241560320 before coming to shortest
terms, which is above 2^30.
Guile rationals can deal with arbitrary precision, but LilyPond has its
own idea of rational numbers.
Just try to use numbers that actually add up to somewhat saner values.
--
David Kastrup
- Problem with scaled durations, Oscar Dub, 2013/01/02
- Re: Problem with scaled durations,
David Kastrup <=
- Re: Problem with scaled durations, Oscar Dub, 2013/01/03
- Re: Problem with scaled durations, David Kastrup, 2013/01/04
- Re: Problem with scaled durations, Trevor Daniels, 2013/01/04
- Re: Problem with scaled durations, David Kastrup, 2013/01/04
- Re: Problem with scaled durations, Trevor Daniels, 2013/01/04
- Re: Problem with scaled durations, Colin Hall, 2013/01/04
- Re: Problem with scaled durations, Marek Klein, 2013/01/04
- Re: Problem with scaled durations, Colin Hall, 2013/01/04