Kaj wrote Saturday, February 21, 2015 9:10 PM
One thing (among others) I still do not understand: why are there three
keys describing the distance between staves and systems? In the Notation
Reference
(http://www.lilypond.org/doc/v2.18/Documentation/notation/flexible-vertical-spacing-paper-variables#structure-of-flexible-vertical-spacing-alists)
one tries to describe how they are defined. But, if I understand it
correct, the effective (resulting) distance will always be the biggest
of the three, hence
effective_distance = max(minimum-distance; basic-distance; padding).
Is there any reason to use three, one should be sufficient. If they were
adding like
resulting_distance = minimum-distance + basic-distance + padding
this could motivate the number, but I cannot read this from the manual.
That is only true "if the page has a ragged bottom". In that case no
stretching or compression is required, and the various spacings are set at
their "natural" values, specified by the effective_distance you show above
(plus anything needed to avoid collisions).
However, if ragged-bottom = ##f, the spacing between the various
elements on the page needs to be adjusted so the page is exactly
filled. That is when all four parameters come into play, as described
on the page you reference above, to control the amount of stretching
or compression required, and how it should be distributed between
the elements on the page.
Trevor