Esempio tipico è una minipage larga ad esempio .5\textwidth. Dentro la minipage \linewidth è pari a .5\textwidth mentre \textwidth e \columnwidth con cambiano.
Ho più di un dubbio sulla correttezza di questa affermazione. Vedi il primo esempio di pagina 59 di questa guida.
Si include un’immagine di larghezza \columnwidth… eppure, come è evidente, l’immagine è larga (meno di metà) della colonna del testo del documento. (Nel documento principale, ad una colonna, \columnwidth = \textwidth.) Mi pare si possa concludere che, in quell’esempio, la \columnwidth sia cambiata.
Dentro una minipage, infatti, viene tutto cambiato: la minipage è trattata come se fosse una pagina di testo adeguata a una giustezza data dall’argomento di minipage.
`\documentclass[a4paper]{article}
\begin{document}
\showthe\textwidth
\showthe\columnwidth
\showthe\linewidth
\begin{minipage}{.5\textwidth}
\showthe\textwidth
\showthe\columnwidth
\showthe\linewidth
\end{minipage}
\end{document}`
Il risultato è
`This is pdfTeXk, Version 3.1415926-1.40.9 (Web2C 7.5.7) (format=latex 2008.9.5) 13 SEP 2008 13:33
entering extended mode
%&-line parsing enabled.
**colwd.tex
(./colwd.tex
LaTeX2e <2005/12/01>
Babel
yphenation, german-x-2008-06-18, ngerman-x-2008-06-18, ancientgreek, ibycus, ar
abic, basque, bulgarian, catalan, pinyin, coptic, croatian, czech, danish, dutc
h, esperanto, estonian, farsi, finnish, french, galician, german, ngerman, mono
greek, greek, hungarian, icelandic, indonesian, interlingua, irish, italian, la
tin, mongolian, mongolian2a, bokmal, nynorsk, polish, portuguese, romanian, rus
sian, sanskrit, serbian, slovak, slovenian, spanish, swedish, turkish, ukenglis
h, ukrainian, uppersorbian, welsh, loaded.
(/usr/local/texlive/2008/texmf-dist/tex/latex/base/article.cls
Document Class: article 2005/09/16 v1.4f Standard LaTeX document class
(/usr/local/texlive/2008/texmf-dist/tex/latex/base/size10.clo
File: size10.clo 2005/09/16 v1.4f Standard LaTeX file (size option)
)
\c@part=\count79
\c@section=\count80
\c@subsection=\count81
\c@subsubsection=\count82
\c@paragraph=\count83
\c@subparagraph=\count84
\c@figure=\count85
\c@table=\count86
\abovecaptionskip=\skip41
\belowcaptionskip=\skip42
\bibindent=\dimen102
)
No file colwd.aux.
\openout1 = `colwd.aux'.
LaTeX Font Info: Checking defaults for OML/cmm/m/it on input line 2.
LaTeX Font Info: … okay on input line 2.
LaTeX Font Info: Checking defaults for T1/cmr/m/n on input line 2.
LaTeX Font Info: … okay on input line 2.
LaTeX Font Info: Checking defaults for OT1/cmr/m/n on input line 2.
LaTeX Font Info: … okay on input line 2.
LaTeX Font Info: Checking defaults for OMS/cmsy/m/n on input line 2.
LaTeX Font Info: … okay on input line 2.
LaTeX Font Info: Checking defaults for OMX/cmex/m/n on input line 2.
LaTeX Font Info: … okay on input line 2.
LaTeX Font Info: Checking defaults for U/cmr/m/n on input line 2.
LaTeX Font Info: … okay on input line 2.
> 345.0pt.
l.3 \showthe\textwidth
?
> 345.0pt.
l.4 \showthe\columnwidth
?
> 345.0pt.
l.5 \showthe\linewidth
?
> 172.5pt.
l.7 \showthe\textwidth
?
> 172.5pt.
l.8 \showthe\columnwidth
?
> 172.5pt.
l.9 \showthe\linewidth
?
LaTeX Font Info: External font `cmex10' loaded for size
(Font) <7> on input line 10.
LaTeX Font Info: External font `cmex10' loaded for size
(Font) <5> on input line 10.
[1
] (./colwd.aux) )
Here is how much of TeX's memory you used:
200 strings out of 493887
2144 string characters out of 1151123
48889 words of memory out of 3000000
3562 multiletter control sequences out of 10000+50000
3640 words of font info for 14 fonts, out of 3000000 for 5000
714 hyphenation exceptions out of 8191
23i,4n,18p,137b,107s stack positions out of 5000i,500n,10000p,200000b,50000s
Output written on colwd.dvi (1 page, 208 bytes).`
Ciao
Enrico