Ciência Rural (Jan 2016)

Likelihood ratio test between two groups of castor oil plant traits

  • Betania Brum,
  • Sidinei José Lopes,
  • Daniel Furtado Ferreira,
  • Lindolfo Storck,
  • Alberto Cargnelutti Filho

DOI
https://doi.org/10.1590/0103-8478cr20151418
Journal volume & issue
no. 0

Abstract

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ABSTRACT: The likelihood ratio test (LRT), to the independence between two sets of variables, allows to identify whether there is a dependency relationship between them. The aim of this study was to calculate the type I error and power of the LRT for determining independence between two sets of variables under multivariate normal distributions in scenarios consisting of combinations of 16 sample sizes; 40 combinations of the number of variables of the two groups; and nine degrees of correlation between the variables (for the power). The rate of type I error and power were calculate at 640 and 5,760 scenarios, respectively. A performance evaluation of the LRT was conducted by computer simulation by the Monte Carlo method, using 2,000 simulations in each scenario. When the number of variables was large (24), the TRV controlled the rate of type I errors and showed high power in sizes greater than 100 samples. For small sample sizes (25, 30 and 50), the test showed good performance because the number of variables did not exceed 12.

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