cops: Cluster Optimized Proximity Scaling

Multidimensional scaling (MDS) methods that aim at pronouncing the clustered appearance of the configuration (Rusch, Mair & Hornik, 2021, <doi:10.1080/10618600.2020.1869027>). They achieve this by transforming proximities/distances with explicit power functions and penalizing the fitting criterion with a clusteredness index, the OPTICS Cordillera (Rusch, Hornik & Mair, 2018, <doi:10.1080/10618600.2017.1349664>). There are two variants: One for finding the configuration directly (COPS-C) with given explicit power transformations and implicit ratio, interval and non-metric optimal scaling transformations (Borg & Groenen, 2005, ISBN:978-0-387-28981-6), and one for using the augmented fitting criterion to find optimal hyperparameters for the explicit transformations (P-COPS). The package contains various functions, wrappers, methods and classes for fitting, plotting and displaying a large number of different MDS models (most of the functionality in smacofx) in the COPS framework. The package further contains a function for pattern search optimization, the “Adaptive Luus-Jaakola Algorithm” (Rusch, Mair & Hornik, 2021,<doi:10.1080/10618600.2020.1869027>) and a functions to calculate the phi-distances for count data or histograms.

Version: 1.11-3
Depends: R (≥ 3.5.0), cordillera (≥ 0.7-2), smacofx
Imports: smacof, analogue, cmaes, crs, dfoptim, GenSA, minqa, NlcOptim, nloptr, pso, rgenoud, Rsolnp, subplex
Suggests: R.rsp, rmarkdown
Published: 2024-06-27
DOI: 10.32614/CRAN.package.cops
Author: Thomas Rusch ORCID iD [aut, cre], Patrick Mair ORCID iD [aut], Kurt Hornik ORCID iD [ctb]
Maintainer: Thomas Rusch <thomas.rusch at>
License: GPL-2 | GPL-3
NeedsCompilation: no
Citation: cops citation info
Materials: NEWS
In views: Psychometrics
CRAN checks: cops results


Reference manual: cops.pdf
Vignettes: A Tutorial on Cluster Optimized Proximity Scaling (COPS)


Package source: cops_1.11-3.tar.gz
Windows binaries: r-devel:, r-release:, r-oldrel:
macOS binaries: r-release (arm64): cops_1.11-3.tgz, r-oldrel (arm64): cops_1.11-3.tgz, r-release (x86_64): cops_1.11-3.tgz, r-oldrel (x86_64): cops_1.11-3.tgz
Old sources: cops archive


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