Third-party software for assuring source code quality is becoming increasingly popular. Tools that evaluate the coverage of unit tests, perform static code analysis, or inspect run-time memory use are crucial in the software development life cycle. More sophisticated methods allow for performing meta-analyses of large software repositories, e.g., to discover abstract topics they relate to or common design patterns applied by their developers. They may be useful in gaining a better understanding of the component interdependencies, avoiding cloned code as well as detecting plagiarism in programming classes. A meaningful measure of similarity of computer programs often forms the basis of such tools. While there are a few noteworthy instruments for similarity assessment, none of them turns out particularly suitable for analysing R code chunks. Existing solutions rely on rather simple techniques and heuristics and fail to provide a user with the kind of sensitivity and specificity required for working with R scripts. In order to fill this gap, we propose a new algorithm based on a Program Dependence Graph, implemented in the SimilaR package. It can serve as a tool not only for improving R code quality but also for detecting plagiarism, even when it has been masked by applying some obfuscation techniques or imputing dead code. We demonstrate its accuracy and efficiency in a real-world case study.
Supplementary materials are available in addition to this article. It can be downloaded at RJ-2020-017.zip
magrittr, SimilaR, nortest, DescTools
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For attribution, please cite this work as
Bartoszuk & Gagolewski, "The R Journal: SimilaR: R Code Clone and Plagiarism Detection", The R Journal, 2020
BibTeX citation
@article{RJ-2020-017,
author = {Bartoszuk, Maciej and Gagolewski, Marek},
title = {The R Journal: SimilaR: R Code Clone and Plagiarism Detection},
journal = {The R Journal},
year = {2020},
note = {https://doi.org/10.32614/RJ-2020-017},
doi = {10.32614/RJ-2020-017},
volume = {12},
issue = {1},
issn = {2073-4859},
pages = {367-385}
}