QuickLaTeX cannot compile formula Error

[johnpeterm]

Description

On some section of the formula, the following error occurs
*** QuickLaTeX cannot compile formula:
\begin{array}{}\ \ \phantom{\rule{1.2em}{0ex}}7.56\phantom{\rule{0.2em}{0ex}}\text{kg}\hfill \ -6.052\phantom{\rule{0.2em}{0ex}}\text{kg}\hfill \ \ \ \phantom{\rule{0.2em}{0ex}}\frac{\phantom{\rule{0.2em}{0ex}}+13.7\phantom{\rule{0.2em}{0ex}}\text{kg}}{15.208\phantom{\rule{0.2em}{0ex}}\text{kg}}=15.2\phantom{\rule{0.2em}{0ex}}\text{kg}\text{.}\hfill \end{array}

*** Error message:
Missing # inserted in alignment preamble.
leading text: $\begin{array}{}
Missing $ inserted.
leading text: ...15.208\phantom{\rule{0.2em}{0ex}}\text{kg}}
Extra }, or forgotten $.
leading text: ...15.208\phantom{\rule{0.2em}{0ex}}\text{kg}}
Missing } inserted.
leading text: ...m}{0ex}}\text{kg}\text{.}\hfill \end{array}
Extra }, or forgotten $.
leading text: ...m}{0ex}}\text{kg}\text{.}\hfill \end{array}
Missing } inserted.
leading text: ...m}{0ex}}\text{kg}\text{.}\hfill \end{array}
Extra }, or forgotten $.
leading text: ...m}{0ex}}\text{kg}\text{.}\hfill \end{array}
Missing } inserted.
leading text: ...m}{0ex}}\text{kg}\text{.}\hfill \end{array}
Extra }, or forgotten $.
leading text: ...m}{0ex}}\text{kg}\text{.}\hfill \end{array}
Missing } inserted.

Expected behaviour

Actual behaviour

[What actually happened]

Steps to reproduce the problem

It happens in random sections of formula of imported book into pressbooks.

System Information

• Openstax Import for Pressbooks: [Enter POI Version here]
  Pressbooks: [Version 5.4.0]
  WordPress: [Version 4.9.7]

[bdolor]

I can reproduce this - the conversion process is from mathml (in the original book) to LaTeX via xsl: https://github.com/BCcampus/pressbooks-openstax-import/tree/dev/inc/import/openstax/xsl

The LaTeX is then rendered via QuickLaTeX image rendering service. Unfortunately equation conversion is not 100% all the time, especially in books with many equations. That said, we've been happy with the results, albeit imperfect.

[johnpeterm]

Despite imperfection, it is huge time saver.

[bdolor]

@johnpeterm - thanks for mentioning that. We agree it's better than it was when it was a purely manual process. Converting an openstax book with equations would take months. That said, there are plans to incrementally improve the performance of this importer, so I'll leave this ticket open for now. Though I'm not sure how it will affect equation transformation, we hope to see some improvements with #71 Thanks for reporting the issue.

[otterscotter]

None of the formulas in this conversion are displaying properly after the import. Any ideas?
Code in the editor:
The magnitude of the charge is independent of the type. Phrased another way, the smallest possible positive charge (to four significant figures) is $+1.602\times10^{-19}\mathrm{C}$, and the smallest possible negative charge is $-1.602\times10^{-19}\mathrm{C}$; these values are exactly equal. This is simply how the laws of physics in our universe turned out.
As displayed in the book:
The magnitude of the charge is independent of the type. Phrased another way, the smallest possible positive charge (to four significant figures) is $+1.602\times10^{-19}\mathrm{C}$, and the smallest possible negative charge is $-1.602\times10^{-19}\mathrm{C}$; these values are exactly equal. This is simply how the laws of physics in our universe turned out.
https://pbooks.scottrobison.net/physics155/chapter/electric-charge

[bdolor]

Could be a number of things, @otterscotter - really depends on a number of things. Most importantly which plugin you're using to to render Math. Is it a problem that can be addressed by making changes to the plugin? If so, you could consider opening a new ticket, or making sure you are using WP QuickLaTeX plugin. This one addresses the larger problem of the transformation working 95% of the time which is a different issue than transformations working 0% of the time. Thanks!

[otterscotter]

Yes, version 3.8.5. Might there be any configuration changes needed? I'm a complete LaTeX noob.

[otterscotter]

Sorry, doesn't look like the screen shot went through...

[bdolor]

If the WP QuickLaTeX plugin was activated prior to and during the import process, then there is no other trickery required. If this is something you can confirm is an issue with the plugin then I encourage you to create a new issue with an eye to giving me enough detail to re-create the issue. If it is a general support request though, I'm afraid I don't have the capacity to be much help.

[otterscotter]

Ha. I just imported Calculus Volume 1 and at first glance, formulas display properly! I'll try re-importing problematic titles again. Thanks!