A MANOVA test for multivariate lognormal observations with a spike at zero, with application to ecological niches of South Africa

Farcomeni, Alessio

doi:10.1002/bimj.201400085

Cited by 3 publications

(3 citation statements)

References 22 publications

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“…In the framework of ANOVA and in the field of likelihood ratio tests, Farcomeni 12 has developed an asymptotic test for multivariate lognormal data with a point mass at zero, generalizing Wilks' lambda and Hotelling's T 2 -test to the case of semicontinuous data. In the same framework, Thulin 13 discusses some parametric and nonparametric multivariate tests for biomarker data with nondetects.…”

Section: Introductionmentioning

confidence: 99%

Multivariate permutation tests for two sample testing in presence of nondetects with application to microarray data

Arboretti

Bathke

Pesarin

et al. 2019

Stat Methods Med Res

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Very often, data collected in medical research are characterized by censored observations and/or data with mass on the value zero. This happens for example when some measurements fall below the detection limits of the specific instrument used. This type of left censored observations is called “nondetects”. Such a situation of an excessive number of zeros in a data set is also referred to as zero-inflated data. In the present work, we aim at comparing different multivariate permutation procedures in two-sample testing for data with nondetects. The effect of censoring is investigated with regard to the different values that may be attributed to nondetected values, both under the null hypothesis and under alternative. We motivate the problem using data from allergy research.

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Section: Introductionmentioning

confidence: 99%

Multivariate permutation tests for two sample testing in presence of nondetects with application to microarray data

Arboretti

Bathke

Pesarin

et al. 2019

Stat Methods Med Res

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“…These methods have only been used for single biospecimen analyses and few methods suitable for multivariate analysis of data with missing values have been developed. Farcomeni (2016) developed a two-part MANOVA test for multivariate lognormal data with a spike at zero. This procedure was applied to ecological data and while it could be applicable to omics data which are often assumed to be log-normally distributed, it has not been evaluated in this context.…”

Section: Introductionmentioning

confidence: 99%

Multivariate two-part statistics for analysis of correlated mass spectrometry data from multiple biological specimens

et al. 2016

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Motivation: High through-put mass spectrometry (MS) is now being used to profile small molecular compounds across multiple biological sample types from the same subjects with the goal of leveraging information across biospecimens. Multivariate statistical methods that combine information from all biospecimens could be more powerful than the usual univariate analyses. However, missing values are common in MS data and imputation can impact betweenbiospecimen correlation and multivariate analysis results. Results: We propose two multivariate two-part statistics that accommodate missing values and combine data from all biospecimens to identify differentially regulated compounds. Statistical significance is determined using a multivariate permutation null distribution. Relative to univariate tests, the multivariate procedures detected more significant compounds in three biological datasets. In a simulation study, we showed that multi-biospecimen testing procedures were more powerful than single-biospecimen methods when compounds are differentially regulated in multiple biospecimens but univariate methods can be more powerful if compounds are differentially regulated in only one biospecimen. Availability and Implementation: We provide R functions to implement and illustrate our method as supplementary information.

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“…The approach can be fruitfully linked to the approach discussed in Dreassi et al (2014) to deal with semicontinuous skewed spatial data. Farcomeni (2016) starts from the definition of an implicitly two part model for a setting where multivariate log-normal data with a point mass at zero in each univariate profile have been observed. The author proposes an asymptotic likelihood ratio test that is shown to generalizes Wilks' λ and Hotelling's T-test to the case of semicontinuous data.…”

mentioning

confidence: 99%

Editorial: Special issue on models for continuous data with a spike at zero

Böhning

Alfó

2016

Biometrical J

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A MANOVA test for multivariate lognormal observations with a spike at zero, with application to ecological niches of South Africa

Cited by 3 publications

References 22 publications

Multivariate permutation tests for two sample testing in presence of nondetects with application to microarray data

Multivariate permutation tests for two sample testing in presence of nondetects with application to microarray data

Multivariate two-part statistics for analysis of correlated mass spectrometry data from multiple biological specimens

Editorial: Special issue on models for continuous data with a spike at zero

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