Mes: septiembre 2020

In this insert we present programs to perform several procedures designed to estimate the parameters of the von Bertalanffy growth function. Three of them are linear derivations from the basic growth equation, and the last one uses a nonlinear regression Read More …

In previous inserts we presented a series of programs to calculate density estimates for univariate data (Salgado-Ugarte et al. 1993, 1995a). We also introduced a series of practical bandwidth rules for histograms, frequency polygons, and kernel density estimators, including cross-validation Read More …

Kernel density estimators are important tools for exploring and analyzing data distributions (see the references in Salgado-Ugarte et al. 1993). However, one drawback of these procedures is the large number of calculations required to compute them. As a consequence, it Read More …

The choice of bandwidth (smoothing parameter) is one of the central problems of density estimation. As we noted in previous inserts (Salgado-Ugarte et al. 1993, 1995), there are several ways to select an appropriate value for this parameter for histograms, Read More …

Mixed distributions -mixtures of normal distributions- arise frequently in biological and ecological data, and the analysis of these mixed distributions is an important topic in fisheries science, particularly when studying species in subtropical and tropical areas. Many samples of fish Read More …