Estimating growth charts via nonparametric quantile regression: a practical framework with application in ecology

• DOI: 10.1007/s10651-012-0232-1
• Publication Date: 2012-12-31T13:57:59Z
• Authors: Vito M. R. Muggeo; Mariangela Sciandra; Agostino Tomasello; Sebastiano Calvo
• Keywords: Growth charts, Nonparametric regression quantiles, Penalized splines, P. oceanica modelling, R software; 0101 mathematics; 01 natural sciences

We discuss a practical and effective framework to estimate reference growth charts via regression quantiles. Inequality constraints are used to ensure both monotonicity and non-crossing of the estimated quantile curves and penalized splines are employed to model the nonlinear growth patterns with respect to age. A companion R package is presented and relevant code discussed to favour spreading and application of the proposed methods.