isocir: An R Package for Constrained Inference Using Isotonic Regression for Circular Data, with an Application to Cell Biology

Abstract

In many applications one may be interested in drawing inferences regarding the order of a collection of points on a unit circle. Due to the underlying geometry of the circle standard constrained inference procedures developed for Euclidean space data are not applicable. Recently, statistical inference for parameters under such order constraints on a unit circle was discussed in Rueda, Fernández, and Peddada (2009) and Fernández, Rueda, and Peddada (2012). In this paper we introduce the R package isocir which provides a set of functions that can be used for analyzing angular data subject to order constraints on a unit circle. Since this work is motivated by applications in cell biology, we illustrate the proposed package using a relevant cell cycle data.