How to use the command 'latexdiff' (with examples)

The latexdiff command is an essential tool for anyone working with multiple versions of LaTeX documents. In academic and professional settings, document revisions are commonplace, and understanding the changes made between versions can be crucial. latexdiff simplifies this process by automatically identifying differences between two LaTeX files and generating a new LaTeX file that highlights these changes. Users can then compile the produced file to visually inspect the edits, saving time and reducing the likelihood of errors in revision tracking.

Use case 1: Determine changes between different versions of a LaTeX file

Code:

latexdiff old.tex new.tex > diff.tex

Motivation:

In the academic and publishing domains, documents often undergo numerous revisions. This use case is for situations where a researcher, student, or author wants to quickly compare an older version of their LaTeX document with a new one to identify changes. This comparison is essential to ensure that critical content has been updated correctly, and that accidental deletions or changes have not occurred. Seeing text differences underlined makes it easy to spot modifications.

Explanation:

• latexdiff: This is the name of the command used to compare two LaTeX documents.
• old.tex: This is the base file, representing the older version of the document. It serves as the benchmark for the comparison.
• new.tex: This file is the version of the document with changes applied. It is compared against old.tex.
• >: This symbol redirects the output of the command to a file.
• diff.tex: This is the output file where the differences between old.tex and new.tex are stored. When compiled, this file will show differences underlined.

Example Output:

When compiled, diff.tex will show sections of text that have changed. Additions will typically be displayed with underlining and perhaps color emphasis, while deletions might be shown with strikethrough or other visual indications of removal. This makes it easy for users to quickly review what has been added, removed, or modified.

Use case 2: Determine changes between different versions of a LaTeX file by highlighting differences in boldface

Code:

latexdiff --type=BOLD old.tex new.tex > diff.tex

Motivation:

This use case is particularly useful for users who prefer a more prominent visual differentiation of changes. In some cases, underlining might not provide enough contrast or visibility, especially for long and complex documents. By highlighting changes in bold, users can gain immediate visual feedback, ensuring that important modifications are not overlooked.

Explanation:

• latexdiff --type=BOLD: The --type flag specifies how changes should be displayed in the output. By setting it to BOLD, modifications will appear in boldface type in the output document.
• old.tex: The older version of the document, used as a baseline for comparison.
• new.tex: The newer version of the document includes changes to be compared.
• >: Redirects the command’s result to a file.
• diff.tex: The output file. When compiled, it will display modifications, with added text in bold and removed text possibly struck out or otherwise annotated.

Example Output:

Upon compiling diff.tex, each text difference relative to the older document may appear in boldface. This enhances visual impact, making differences immediately noticeable, which is crucial for proofreading and finalizing drafts before submission or publication.

Use case 3: Determine changes between different versions of a LaTeX file, and display minor changes in equations with both added and deleted graphics

Code:

latexdiff --math-markup=fine --graphics-markup=both old.tex new.tex > diff.tex

Motivation:

This specific use case caters to documents that contain a significant amount of mathematical content and graphical elements. Academic and scientific documents routinely feature equations and figures that may change subtly between revisions. By using this command, users can ensure that slight adjustments in mathematical formulas or figures do not go unnoticed, maintaining the precision and accuracy essential in such fields.

Explanation:

• latexdiff: The command to compare LaTeX documents.
• --math-markup=fine: This flag instructs latexdiff to use a nuanced markup style to denote even minor changes in equations. This level of detail allows users to capture slight adjustments to formulas that could alter their meaning or application.
• --graphics-markup=both: This option specifies that both additions and deletions of graphics should be highlighted. This ensures comprehensive tracking of changes in graphical elements of the document, helping users to manage visual content revisions effectively.
• old.tex: The previous version of the LaTeX file.
• new.tex: The newer version, containing edits.
• >: Redirects the output to a specified file.
• diff.tex: The generated file that will show changes when compiled.

Example Output:

Upon compiling the output, the document will reflect even small changes in equations with specific markup, giving a clear view of what has been altered. It might use different colors or symbols to show changes in mathematical expressions, and both added and deleted graphics will be marked, allowing users to assess how visual content has evolved.

Conclusion:

latexdiff is a versatile tool that greatly enhances the efficiency and accuracy of document revision processes in LaTeX. By providing various markup options, it accommodates different user preferences and document needs, making it invaluable for authors, researchers, and students who rely on LaTeX for their document preparation. These examples demonstrate just a few capabilities of latexdiff, highlighting its importance in the management of LaTeX document versions.