This repository holds digital resources associated with the article "Mathematical notation in REDCap online data collection instruments" [1]. That article discusses rendering LaTeX mathematical notation as images in REDCap [2, 3] online surveys. An example survey is provided, using questions drawn from a study of students' perceptions of physico-mathematical concepts [4].
Equations are SVG images generated via LuaLaTeX and pdftocairo.
Adapted from [1].
| File | Notes |
|---|---|
assets/equation[dd].svg |
Vector graphics renderings of equations. |
src/build.ps1 |
PowerShell build script. |
src/latex/equation[dd].texsrc/latex/typeface-config.tex |
LaTeX equation generation files. |
src/physico-mathematical-concepts.zip |
REDCap instrument. |
| Software | Notes |
|---|---|
| LuaLaTeX | Available here. Free in major TeX distributions. |
| PowerShell |
Free. Linux, macOS: available here. Windows: included in Windows 7 and Windows Server 2008 R2 onwards. |
| REDCap |
Details here. Free for non-profit, institutional use. Fee-based cloud or other hosted service otherwise. |
| pdftocairo |
Free. Linux, macOS: available in poppler-utils. Windows: available in poppler-utils or the MiKTeX package miktex-poppler-bin. |
Please ensure the LuaLaTeX environment has the following packages installed:
- GFSNeohellenicMath.
- standalone.
- unicode-math.
Typesetting the LaTeX files has been tested with LuaLaTeX, bundled with MiKTeX.
Conversion of LuaLaTeX-output PDF files to SVG files has been tested with pdftocairo.
Import of the instrument file has been tested with REDCap, accessed via a browser. Successful online rendering of the data collection instrument (a survey) was confirmed.
Versions of each testing environment component are given below.
| Type | Component | Version |
|---|---|---|
| Platform | Operating system | Windows 11, 25H2 (OS Build 26200.8737) |
| " | Browser | Microsoft Edge, 146.0.3856.62 |
| Software | LuaLaTeX | LuaHBTeX, 1.25.7 |
| " | MiKTeX | 26.5 |
| " | PowerShell | 5.1 |
| " | REDCap | 16.1.1 |
| " | pdftocairo | 24.04.0 |
| LuaLaTeX package | GFSNeohellenicMath | 1.02 |
| " | standalone | 1.5a |
| " | unicode-math | 0.8r |
Pre-built vector graphics (SVG) files of example equations, for online display,
are available in the directory assets.
The SVG files were generated using the PowerShell build script src/build.ps1.
It may be invoked by opening PowerShell, navigating to the directory src,
then making a platform-relevant call:
./build.ps1.\build.ps1The build script operates as follows:
-
LuaLaTeX compiles PDF files from LaTeX mathematical markup. Example LaTeX mathematical markup files are available in the directory
src/latex. Those files use thestandalonedocument class to crop PDF bounds to mathematics content. -
pdftocairo converts the PDF files to SVG format.
-
To improve equation accessibility, ARIA roles with MathSpeak labels are set in the SVG files. LaTeX to MathSpeak converters are available online.
REDCap instruments can be configured to display images online with the REDCap
Online Designer. Images can be included in instrument field labels, for example,
by specifying a relevant src attribute of a HTML <img> tag. Target images
may be stored remotely, or locally to a REDCap environment via the REDCap File
Repository.
An example REDCap data collection instrument is available,
src/physico-mathematical-concepts.zip. It demonstrates use of LaTeX to style
and typeset mathematical notation online, albeit indirectly, via LaTeX rendered
as images.
The instrument ZIP file may be uploaded into a REDCap project.
Note
The ZIP files holds links to images, that work with a specific REDCap File Repository. They will need modification for your REDCap project, e.g., via the REDCap Online Designer.
The associated images are the SVG files in assets. They may also be uploaded
into a REDCap project File Repository, or other remotely accessible location,
and associated links updated in Online Designer. Note, the example survey used
HTML/CSS for manually fine-tuning equation image sizes and positioning.
In testing the instrument in REDCap, the survey design options were set to use the Arial font. Text in field labels was explicitly set to use Arial via the Online Designer. LaTeX files were also configured to output Arial content.
Font choice is a matter for REDCap instrument designers. Consistency across design elements, such as that described here, is however recommended.
This work used REDCap electronic data capture tools [2, 3]. REDCap (Research Electronic Data Capture) is a secure, web-based software platform designed to support data capture for research studies, providing:
- an intuitive interface for validated data capture,
- audit trails for tracking data manipulation and export procedures,
- automated export procedures for seamless data downloads to common statistical packages, and
- procedures for data integration and interoperability with external sources.
This repository used Gemini 3.5 Flash [5] as an assistive tool to provide example JSON, LaTeX and PowerShell syntax. All other repository code, logic and architecture were created by the author.
-
T. Stenborg, "Mathematical notation in REDCap online data collection instruments", TUGboat, vol. 47, no. 1, pp. 89–90, Apr. 2026, doi: 10.47397/tb/47-1/tb145stenborg-redcap.
View PDF View at publisher SciX -
P. A. Harris, R. Taylor, R. Thielke, J. Payne, N. Gonzalez and J. G. Conde, "Research electronic data capture (REDCap)—A metadata-driven methodology and workflow process for providing translational research informatics support", J. Biomed. Inform., vol. 42, no. 2, pp. 377–381, Apr. 2009, doi: 10.1016/j.jbi.2008.08.010.
View PDF View at publisher SciX -
P. A. Harris et al., "The REDCap consortium: Building an international community of software platform partners", J. Biomed. Inform., vol. 95, Jul. 2019, Art. no. 103208, doi: 10.1016/j.jbi.2019.103208.
View PDF View at publisher SciX -
K. P. Mwangala, and O. Shumba, "Physico-mathematical Conceptual Difficulties among First Year Students Learning Introductory University Physics", Am. J. Educ. Res., vol. 4, no. 17, pp. 1238–1244, Nov. 2016.
View at publisher SciX -
Gemini 3.5 Flash. (Large language model, May 2026 release). Google. [Online]. Available: google.com.