A MANOVA test for multivariate lognormal observations with a spike at zero, with application to ecological niches of South Africa. Issue 2 (4th November 2014)

• Record Type: Journal Article
• Authors: Farcomeni, Alessio
• Is Part Of: Biometrical journal. Volume 58:Issue 2(2016:Mar.)
• Page Start: 320
• Page End: 330
• Publication Date: 2014-11-04
• Subjects: Excess zeros -- Likelihood ratio test -- Hotelling T‐test -- Wilks' lambda; Biometry -- Periodicals; Medical statistics -- Periodicals; 570.15195
• DOI: 10.1002/bimj.201400085
• Languages: English
• ISSNs: 0323-3847

Abstract

Abstract : We develop an asymptotic likelihood ratio test for multivariate lognormal data with a point mass at zero in each dimension. The test generalizes Wilks' lambda and Hotelling T ‐test to the case of semicontinuous data. Simulations show that the resulting test statistic attains the nominal Type I error rate and has good power for reasonable alternatives. We conclude with an application to exploration of ecological niches of trees of South Africa.