We propose rank-based estimators of principal components, both in the one-sample and, under the assumption of <italic>common principal components</italic>, in the <italic>m</italic>-sample cases. Those estimators are obtained via a rank-based version of Le Cam's one-step method, combined with an estimation of <italic>cross-information...</italic>

We tackle the classical two-sample spherical location problem for directional data by having recourse to the Le Cam methodology, habitually used in classical linear multivariate analysis. More precisely we construct locally and asymptotically optimal (in the maximin sense) parametric tests,...

One-sample and multi-sample tests on the concentration parameter of Fisher-vonMises-Langevin (FvML) distributions have been well studied in the literature. However,only very little is known about their behavior under local alternatives, whichis due to complications inherent to the curved nature...