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Modelling animal growth in random environments: An application using nonparametric estimation
Author(s) -
Filipe Patrícia A.,
Braumann Carlos A.,
Brites Nuno M.,
Roquete Carlos J.
Publication year - 2010
Publication title -
biometrical journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.108
H-Index - 63
eISSN - 1521-4036
pISSN - 0323-3847
DOI - 10.1002/bimj.200900273
Subject(s) - nonparametric statistics , parametric statistics , parameterized complexity , estimation , mathematics , stochastic differential equation , diffusion , parametric model , econometrics , functional data analysis , stochastic process , random effects model , mathematical optimization , computer science , statistics , algorithm , physics , engineering , thermodynamics , medicine , meta analysis , systems engineering
We study a stochastic differential equation growth model to describe individual growth in random environments. In particular, in this paper, we discuss the estimation of the drift and the diffusion coefficients using nonparametric methods for the case of nonequidistant data for several trajectories. We illustrate the methodology by using bovine growth data. Our goal is to assess: (i) if the parametric models (with specific functional forms for the drift and the diffusion coefficients) previously used by us to describe the evolution of bovine weight were adequate choices; (ii) whether some alternative specific parameterized functional forms of these coefficients might be suggested for further parametric analysis of this data.