A test for directional-linear independence, with applications to wildfire orien...

• Author(s): García-Portugués, Eduardo ; Barros, Ana M.G. ; Crujeiras, Rosa M. ; González-Manteiga, Wenceslao ; Pereira, J.M.C.
• Date: 2014
• Persistent ID: http://hdl.handle.net/10400.5/6996
• Origin: Repositório da UTL
• Subject(s): directional data; directional-linear density; independence test; nonparametric estimation; permutations; wildfires
• Document Type: Article
• Language: English

Description

Original Paper A nonparametric test for assessing the independence between a directional random variable (circular or spherical, as particular cases) and a linear one is proposed in this paper. The statistic is based on the squared distance between nonparametric kernel density estimates and its calibration is done by a permutation approach. The size and power characteristics of various variants of the test are investigated and compared with those for classical correlation-based tests of independence in an extensive simulation study. Finally, the best-performing variant of the new test is applied in the analysis of the relation between the orientation and size of Portuguese wildfires