LyX ⇒ what exactly is SmallSkip and etc.?

[lyxrocks]

in lyx tutorial it says

SmallSkip, MedSkip and BigSkip are LaTeX sizes which depend on the font size of the document.

well, let's say if my font is 12(default i believe), then how much exactly are SmallSkip MedSkip and BigSkip? in terms of pt for example.

i tried googling it, but couldn't find a definite answer.

[cgnieder]

They are defined in the LaTeX kernel (a file called latex.ltx) like follows:

Code: Select all

\def\smallskip{\vspace\smallskipamount}
\def\medskip{\vspace\medskipamount}
\def\bigskip{\vspace\bigskipamount}
\newskip\smallskipamount \smallskipamount=3pt plus 1pt minus 1pt
\newskip\medskipamount   \medskipamount  =6pt plus 2pt minus 2pt
\newskip\bigskipamount   \bigskipamount =12pt plus 4pt minus 4pt

As you can see they're not depending on the font size.

Regards

[Stefan Kottwitz]

You can print it out by this TeX code:

Code: Select all

\the\smallskipamount

Similar for the other skips. I attach a LyX document, all default, which prints those values.

skips-lyx.png (3.36 KiB) Viewed 31077 times

skips-values.png (7.28 KiB) Viewed 31077 times

Stefan

[lyxrocks]

thank you guys so much!!!

[scottkosty]

They are defined in the LaTeX kernel (a file called latex.ltx) like follows:

As you can see they're not depending on the font size.

Regards

Interesting. But does whether LaTeX chooses to go for the upper part of the range (3pt plus 1pt) or the lower part of the range (3pt minus 1pt) depend on the font size? Or only on other factors that have nothing to do with the font size?

[cgnieder]

You might know that TeX (and hence LaTeX) has different modes. Two of them being the horizontal and the vertical mode. TeX is in horizontal mode when it builds a paragraph and in vertical mode when it connects different paragraphs to build pages (roughly speaking).

This skips are added to the vertical list so they they may stretch or shrink according to LaTeX's page-building mechanism. They are used for example to avoid widows or orphans since they allow the page to stretch or shrink by the given amount at the place where they're used.

Regards

[scottkosty]

You might know that TeX (and hence LaTeX) has different modes. Two of them being the horizontal and the vertical mode. TeX is in horizontal mode when it builds a paragraph and in vertical mode when it connects different paragraphs to build pages (roughly speaking).

This skips are added to the vertical list so they they may stretch or shrink according to LaTeX's page-building mechanism. They are used for example to avoid widows or orphans since they allow the page to stretch or shrink by the given amount at the place where they're used.

Regards

Thanks cgnieder I did not know that. I would like to suggest a change to the text in User Guide that caused the initial confusion and curiosity. I will suggest adding a table related to what you and Stefan gave in your initial posts. But I'm not sure how to modify the text, which I reproduce below. Any ideas?

To add extra vertical space above or below a paragraph, use the Insert->Formatting->Vertical Space dialog. There you find the following sizes:

SmallSkip, MedSkip and BigSkip are LaTeX sizes which depend on the font size of the document. DefSkip is the skip adjusted in the dialog Document-> Document Settings for the paragraph separation. If you use indentation to separate paragraphs DefSkip is equal to MedSkip.

Note that all the LyX documentation is available online from http://wiki.lyx.org/LyX/DocumentationDevelopment

[cgnieder]

I am not sure I want to recommend any text as I am no expert on the page building stuff at all. There is however quite some material to read in the texbook and in texbytopic.

As an addition to what I previously said:

\smallskip, \medskip, \bigskip and all other vertical rubber lengths depend on the material added to a page like paragraphs (and their possible shapes), graphics, tables… and on such things as the values of the \widowpenalty, the \clubpenalty. In a way they also depend on the font size as the font size influences line lengths and paragraph shapes which in turn influence the page…

Regards

[scottkosty]

In a way they also depend on the font size as the font size influences line lengths and paragraph shapes which in turn influence the page…
Regards

This is why I'm not sure how to change the text. I guess I'll leave it.

Thanks,

Scott