Implements Generic Composite Similarity Measure R package GCSM version 0.2.0 Provides implementation of the generic composite similarity measure (GCSM) described in Liu et al. (2020) <doi:10.1016/j.ecoinf.2020.101169>. The implementation is in C++ and uses 'RcppArmadillo'. Additionally, implementations of the structural similarity (SSIM) and the composite similarity measure based on means, standard deviations, and correlation coefficient (CMSC), are included. Software Imports: Rcpp LinkingTo: Rcpp, RcppArmadillo Suggests: testthat Yadong Liu <liuyadong828@gmail.com> Comprehensive R Archive Network (CRAN) Yadong Liu [aut, cre] (ORCID: <https://orcid.org/0000-0002-1283-3451>) MIT + file LICENSE (https://CRAN.R-project.org/package=GCSM/LICENSE) 2025-10-14 application/tgz https://CRAN.R-project.org/package=GCSM doi:10.32614/CRAN.package.GCSM