I am working on an instructor copy of a lab manual in Pressbooks. I am making all completed answers in the instructor copy be blue. Normal Latex equations format fine in all exports. However, I realized today that in the PDF export for digital distribution, Latex formulas that have been formatted blue using the \color{blue} command result in a notification in the PDF export of “Formula Does Not Parse”. It exports fine in the Web Book, but not in the PDF exports. Is this a CSS issue? I had a similar sort of problem with TablePress.
Latex code:
I’m actually not sure. I add the Latex code directly to the text for each chapter.
The book is here: https://kstatelibraries.pressbooks.pub/soilslabmanual/. The chapter I’m having issues with is not publicly available, but is titled “Instructor Copy of Chapter 10 - Soil Water Measurement and Movement”
My PDF’s are not displaying LaTeX equations ([…]); instead they are displaying the LaTeX code. They display fine in web form. I am using MathJax. Here are a couple of examples:
@ColbyDigsSoil it looks like your book is using MathJax. I don’t see the LaTeX expressions you’re having trouble with in that chapter. I’d recommend sending an email to our premium support address which includes the specific equations that aren’t parsing and a chapter where they can be found and/or a PDF file where the output isn’t being included.
@Ana your issue looks different to me. I’m not sure why initial expressions are rendering correctly in the PDF but later ones aren’t. To debug, I’d need to see the book where you’re having problems or the full contents of the text editor for the chapter in question. Can you share a URL?
@Ana before you share the URL, you should check to make sure that the expressions that aren’t rendering in your export files are in fact wrapped in [latex] [/latex] shortcodes. Most of the time we find that PDF errors like the ones I see in your example are the result of missing shortcodes. At present our export routines need the [latex] shortcode flags to know that they should convert the content in between them into images rendered with LaTeX for our EPUB and PDF exports, which can’t use the MathJax javascript library to render the math like our webbooks can.
I’m replying here to document the solution that I received from Thomas from Pressbooks. The original code I used was like this:
[latex]\color{blue}…[/latex]
However, I needed to add curly brackets around the code that is to be colored in blue, like this:
[latex]\color{blue}{…}[/latex]
Here is the excellent explanation from Thomas:
The distinction between the two is that the former syntax is a declaration of a color change, while the latter is a command form that takes the text to be colored as an argument. It’s not clear to me why the PDF is able to parse the latter and not the former, but this should solve the issue without affecting the appearance of the web book.
This worked for my exports and does in fact still look great in the web book. Thanks Thomas, Steel, and Pressbooks for the help.
@gschmalz can you provide some example of math expressions that are rendering as expected in the webbook but not in the exports? I suspect this has to do with the regular expression targeting we use to identify math and replace it with an image for export formats which don’t have native support for the javascript needed by mathjax, but won’t know for sure until we see some examples and are able to replicate them.
Thank you for getting back to me. Examples are
[1\in A,\quad 2\in A,\quad 3\in A, \quad 4\not\in A.]
[latex]\frac12[/latex] and [latex]\frac24[/latex] in a footnote
[A\times B={(a,b)\mid a\in A, b\in B}.]
\begin{align*}
|a + b| & = – (a + b) \ & = -a – b\
& = -a + (-b) \
& \leq |a| + |b|,
\end{align*}
It comes out fine in the preview but not in the exported files (pdf).
