[[abstract]]We use both the conventional and more recently developed methods of cluster analysis to study the data of extrasolar planets (exoplanets). Using the data set with planetary mass M, orbital period P and orbital eccentricity e, we investigate the possible clustering in the ln M, ln P, ln P-ln M, e and ln P-e spaces. There are two main implications: (1) mass distribution is continuous, and (2) orbital population could be classified into three clusters, which correspond to the exoplanets in the regimes of tidal, ongoing tidal and disc interaction, respectively.
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