LaTeXStrings

This is a small package to make it easier to type LaTeX equations in string literals in the Julia language, written by Steven G. Johnson.

With ordinary strings in Julia, to enter a string literal with embedded LaTeX equations you need to manually escape all backslashes and dollar signs: for example, $\alpha^2$ is written \$\\alpha^2\$. Also, even though IJulia is capable of displaying formatted LaTeX equations (via MathJax), an ordinary string will not exploit this. Therefore, the LaTeXStrings package defines:

• A LaTeXString class (a subtype of String), which works like a string (for indexing, conversion, etcetera), but automatically displays as text/latex in IJulia.

• L"..." and L"""...""" string macros which allow you to enter LaTeX equations without escaping backslashes and dollar signs (and which add the dollar signs for you if you omit them).

LaTeXStrings does not do any rendering — its sole purpose is to make it easier to enter LaTeX-rendered strings without typing a lot of backslash escapes, as well as providing a type to tell display backends to use LaTeX rendering if possible.

Other packages like plotting software, Jupyter notebooks, Pluto, etcetera, are responsible for the LaTeX rendering (if any). For example, they might use MathJax, MathTeXEngine.jl, or other renderers. LaTeXStrings only provides the LaTeX text to these backend, and has no influence on what LaTeX features (if any) are supported.

After installing LaTeXStrings with Pkg.add("LaTeXStrings") in Julia, run

using LaTeXStrings

to load the package. At this point, you can construct LaTeXString literals with the constructor L"..." (and L"""...""" for multi-line strings); for example L"1 + \alpha^2" or L"an equation: $1 + \alpha^2$". (Note that $ is added automatically around your string, i.e. the string is interpreted as an equation, if you do not include $ yourself.)

If you want to perform string interpolation (inserting the values of other variables into your string), use %$ instead of the plain $ that you would use for interpolation in ordinary Julia strings. For example, if x=3 is a Julia variable, then L"y = %$x" will produce L"y = 3".

You can also use the lower-level constructor latexstring(args...), which works much like string(args...) except that it produces a LaTeXString result and automatically puts $ at the beginning and end of the string if an unescaped $ is not already present. Note that with latexstring(...) you do have to escape $ and \: for example, latexstring("an equation: \$1 + \\alpha^2\$"). Note that you can supply multiple arguments (of any types) to latexstring, which are converted to strings and concatenated as in the string(...) function.

Finally, you can use the lowest-level constructor LaTeXString(s). The only advantage of this is that it does not automatically put $ at the beginning and end of the string. So, if for some reason you want to use text/latex display of ordinary text (with no equations or formatting), you can use this constructor. (Note that IJulia only formats LaTeX equations; other LaTeX text-formatting commands like \emph are ignored.)

This package was written by Steven G. Johnson, and is distributed under the MIT/expat license (see the LICENSE.md file).