The Coupler: a new bibliometric tool for relational citation, bibliographic coupling and co-citation analysis.

Introduction: The use of programming languages in the context of Metric Information Studies has gained ground among the scientific community in the area as they are practical, free or have low computational cost. Objectives: To present a new, free and alternative bibliometric tool, aimed at relational citation analysis, focusing on bibliographic coupling, built on the R programming language, entitled The Coupler. Methodology: We ground the relational analysis of citation, co-citation and bibliographic coupling from a mathematical perspective and present the source code of the tool and the conditions under which it was built with its access granted for all. We use generic data and expose all its features to test the tool; and to demonstrate the use with real data, we operate bibliometric, patentometric, altmetric and natural language data. Results: The tool builds citation, coupling and co- citation matrices, in addition to calculating normalized values via Salton's Cosine and Jaccard Index of the bibliographic coupling frequencies. Furthermore, The Coupler builds bibliographic coupling networks and identifies the coupling units responsible for each coupling pair; the latter feature, a distinct result for traditional bibliometric software. Conclusion: The paper concludes that the tool behaves as expected and satisfactorily when processing both generic data and bibliometric, patentometric, altmetric and natural language data. Among the results, especially and differentiating from other software, we highlight the identification of coupling units, and calculations of normalized coupling frequencies via Salton's Cosine and Jaccard Index. [ABSTRACT FROM AUTHOR]