# Converting greek utf letters to latex symbols

I have a collection of notes on my iPad, written using a markdown editor/viewer (trunk notes) that does not understand latex, but does display greek. Is there a simple way to convert the greek letters (e.g. convert the UTF-8 symbol 0xCEB1, α) to their latex equivalents (\alpha)? I am using pandoc for the conversion, which is pasting a LaTeX header onto the output before conversion to TeX or ConTeXt.

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Do you need them also in text or only in math? –  egreg Jun 21 '12 at 14:38
Both. I'm placing some short notes inline, and putting longer equations in center /center tags. The app doesn't understand latex, so I am displaying it as HTML on the iPad, but would like to translate the notes to LaTex on my computer. One path is markdown->html->pdf, but that is rather ugly. –  Bill Jun 25 '12 at 2:51

I use the following code to make unicode symbols work both as normal text and in mathmode. But then xelatex is needed to compile it:

\usepackage{fontspec}
\setmainfont[Ligatures=TeX]{STIXGeneral}

\def\textalpha{α} \catcode\α=\active \defα{\relax\ifmmode \alpha \else \textalpha \fi}


Also you need some suitable font, STIX works for me.

If you want to actually replace the unicode characters in the source code, that is a different issue. I don't know what kind of tools are available in your environment. I would compile a list of replacements like α \alpha and then write a small script that executes those in order. E.g. there is the replace utility on linux which does one such replacement.

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I'll take a look at xelatex. Thanks –  Bill Jun 21 '12 at 11:54
\usepackage{newunicodechar} and then \newunicodechar{α}{\ifmmode\alpha\else α\fi} is easier. :) However, with unicode-math and XITS Math as math font (also with other fonts, I believe) it works out of the box. –  egreg Jun 21 '12 at 14:34
@egreg: Thanks for the hint. Of course as I only have to do this once in some custom package, it is not really an effort. Still having it work out of the box would be great. I actually did this when unicode-math didn't work properly yet. Also, pmav99 uses the xgreek package, is that necessary? –  canaaerus Jun 21 '12 at 14:42
No it is not. I just copy pasted...! I'll remove it. –  pmav99 Jun 21 '12 at 14:50

In ConTeXt (both MkIV and MkII with utf-8 encoding), Greek letters work out of the box in text and math mode. (You need a text font with Greek letters)

\starttext
α $α$
\stoptext


With MkIV, Unicode characters behave like ASCII characters, so $\hat α$ is same as $\hat {α}$. In MkII, you need to use the latter form.

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Expanding Canaaerus answer In xelatex, package unicode-math allows you to use greek characters in math-mode. Check the following minimum example.

\documentclass{article}

% font selection for normal text
\usepackage{fontspec}

% Packages needed for mathematics
\usepackage{amsmath}
\usepackage{unicode-math}

% Fonts
\setmainfont[Mapping=tex-text]{Linux Libertine O}
\setmathfont{XITS Math}

\begin{document}

$$a = α + b + β^2_i$$

\end{document}


## Fonts

The fonts that you may use are the following ones (they must be installed in your OS' standard font folder)

• Asana-Math. Free font created by Apostolos Syropoulos.
• Stix
• Xits, fork of Stix
• Neo Euler
• Latin Modern Math, OpenType version of the classic TeX font.
• Cambria Math. Proprietary font, distributed with Microsoft software (e.g. MS Office)

## Edit

Note though that a and \alpha are different symbols! If you want to convert α to a`then the previous approach cannot be used. If that is what you need, then it shouldn't be too difficult to write a script (e.g. in perl or python) that would parse your notes and make the replacements.

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Your links to Stix and Xits do not work. Maybe you mean ctan.org/pkg/stix and ctan.org/pkg/xits ? –  canaaerus Jun 21 '12 at 14:55
Thank you. I was copy-pasting that too. I will fix them. –  pmav99 Jun 21 '12 at 14:57
Do greek letters also work in text mode with lualatex/fontspec/unicode-math? –  Aditya Jun 21 '12 at 15:03
@Aditya I am not really sure. In principle, I believe they should but I am not a LuaLaTeX user. I am mostly interested in multilingual texts. Last time I tried, LuaLaTeX had some problems with greek, so I haven't spend time with it. –  pmav99 Jun 21 '12 at 15:57