LyX ⇒ how to switch the language between text and math?

[ciradu]

I need to know if there is a posibility for automaticaly change the language between text and math mode. I use romanian in text, but I need english when I insert math formula because of the keyboard layout diferences.

[Stefan Kottwitz]

There are two hooks which can be used:

• \everymath is called every time when it's switched to inline math,
• \everydisplay is called every time when it's switched to displayed math, for example in equation environments.

Here's a complete demonstration example, where English is used for normal text, and German is used for math (and text in math):

Code: Select all

\documentclass{article}
\usepackage[ngerman,english]{babel}% loading two languages
\everymath{\selectlanguage{ngerman}}
\everydisplay{\selectlanguage{ngerman}}
\usepackage{amsmath}
\usepackage{parskip}
\begin{document}
tes"-ting english% ngerman shortcut "- doesn't work, but is visible instead
                 % i.e. ngerman is not active, but english

$\text{tes"-ting ngerman}$% here, "- works and is hidden, ngerman is active

tes"-ting english% again, ngerman shortcut "- doesn't work, english is active
\[ \text{tes"-ting ngerman} \]% also here, "- works and is hidden, ngerman is active
tes"-ting english% ngerman shortcut "- doesn't work any more, english is active again
\end{document}

language-switching.png (6.66 KiB) Viewed 6173 times

Stefan

[ciradu]

Thank you for your effort, but I don't know how to implement your solution to make it work in my documents.

[cgnieder]

You need to add

Code: Select all

\usepackage[ngerman,english]{babel}% last language in list will be document language
\everymath{\selectlanguage{ngerman}}
\everydisplay{\selectlanguage{ngerman}}

(or which language you want to have inside math) to the document preamble under Document>Settings>LaTeX Preamble.

Make sure you also choose language=none in the language settings.

Regards

[ciradu]

I did this, but I can't see any difference. It doesn't automaticaly change my keyboard layout.
Thanks.

[Stefan Kottwitz]

The code above changes the language support, such as hyphenation. However, the keyboard layout depends on your operating system and this cannot be changed by LaTeX, except making external calls to a software which changes the keyboard layout. You would need such a software first.

Stefan

[ciradu]

Now I understand. Thanks for your help.