Re: page-limit-inter-system-space

[Richard Shann]

On Mon, 2021-02-08 at 20:53 +0100, Xavier Scheuer wrote:
> On Mon, 8 Feb 2021 at 19:28, Richard Shann <richard@rshann.plus.com>
> wrote:
> >
> > In a multi-movement piece with each movement starting on a new page
> it
> > happens by default that if one movement is very short it will be
> spread
> > out to fill the page. This can be difficult to read as the systems
> are
> > so far apart. I would like to tell LilyPond to limit the space
> between
> > systems to avoid this (leaving blank space below the movement).
> > I've come across page-limit-inter-system-space but can't find the
> > documentation for it.
> > I've been testing various values in the following code without
> success.
> >
> >
> 8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><
> >
> > \version "2.20.0"
> > music = {\repeat unfold 30 c'' }
> > \paper {
> >          page-limit-inter-system-space = ##t
> >          page-limit-inter-system-space-factor = #0.2
> >        }
> > \score {
> >         \music
> > }
> > \pageBreak
> > \score {
> >         \music     
> > }
> >
> >
> 8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><8><
> >
> > Can someone suggest how to make these two movements look the same
> on
> > the page?
> 
> Hello,
> 
> I do not find any mention of "page-limit-inter-system-space" in the
> documentation (in fact a search of this term on the whole website
> lilypond.org does not give any results!).
> Where have you heard about it?

It was sitting around as one of the options to set in Denemo, no one
noticed it had stopped working over a decade ago...
> 
> AFAICS in lilypond's code on gitlab this variable was introduced in a
> commit 13 years ago but removed 11 years ago...
> https://gitlab.com/lilypond/lilypond/-/commit/2d817f0288ab1e90fe6258a
> eae34d9466043cdbf
> https://gitlab.com/lilypond/lilypond/-/commit/d062d6527a8a10e32d5a092
> 0a28a3ac029ba14ef
> 
> In your case I would use different \bookpart with different \paper
> containing, or not, ragged(-last)-bottom.

Thank you - and to all the others who pointed to \bookpart, this
answers perfectly the specific question I asked viz. how to make a
short movement not spread out to fill the page.
It does still leave the problem that lead to the introduction of page-
limit-inter-system-space as described in your first link:

"When only a couple of flat systems are placed on a page, the resulting
vertical spacing may be non-eleguant: one system at the top of the page,
and the other at the bottom, with a huge gap between them. To avoid this
situation, the space added between the systems can be limited. This
feature is activated by setting to @code{#t} the
@code{page-limit-inter-system-space} variable in the @code{\paper}
block. The paper variable @code{page-limit-inter-system-space-factor}
determines how much the space can be increased: for instance, the value
@code{1.3} means that the space can be 30% larger than what it would be
on a ragged-bottom page."

This problem remains because it is nicer if the music expands as much
as is reasonable and then leaves blank space, rather than suddenly
retreating up the page when the spacing is becoming unpleasant
resulting in a large blank space at the bottom.

Looking in the second link you gave, where the feature was removed, I
don't see an explanation as to why it was removed: so I wonder if there
is some other way of limiting the system to system spacing so that it
spreads out to fill the page only to a limited extent. I can always
manually insert blank space after the movement, but it would be nicer
not to have to design the amount of space every time it happens -
indeed nicer not to have to intervene at all.

Many thanks for the responses,

Richard