npbr: A Package for Nonparametric Boundary Regression in R

Abstract

The package npbr is the first free specialized software for data edge and frontier analysis in the statistical literature. It provides a variety of functions for the best known and most innovative approaches to nonparametric boundary estimation. The selected methods are concerned with empirical, smoothed, unrestricted as well as constrained fits under both single and multiple shape constraints. They also cover data envelopment techniques as well as robust approaches to outliers. The routines included in npbr are user friendly and afford a large degree of flexibility in the estimation specifications. They provide smoothing parameter selection for the modern local linear and polynomial spline methods as well as for some promising extreme value techniques. Also, they seamlessly allow for Monte Carlo comparisons among the implemented estimation procedures. This package will be very useful for statisticians and applied researchers interested in employing nonparametric boundary regression models. Its use is illustrated with a number of empirical applications and simulated examples.

Effect of strip shelterwood-cuts on the crown morphology plasticity of natural regeneratedPinus tabuliformissaplings in northeastern China

“…Generally, approximately 12-15% of the total variation in the rate of regeneration contributes to the differences in stands and shelterwood-cut strips (Pliūra, Kundrotas & Suchockas, 2000). Crown morphology plasticity is a desirable sapling characteristic, and analysing crown morphology plasticity of saplings from shelterwood-cut strips and uncut strips is essential in evaluating the effect of shelterwood-cut strips on natural regeneration (Biging & Dobbertin, 1992;Mclaughlin, Wullschleger & Nosal, 2003;Crecente-Campo et al, 2009;Daouia, Laurent & Noh, 2017). To ensure homogeneous growing conditions regarding light availability, all saplings were randomly selected, but the belts maintained at a 2-m width in the centre of each shelterwood-cut strip or uncut strip.…”

A copula-based time series model for global horizontal irradiation

“…There is not much literature on statistical estimation methods for such bounds. Daouia et al (2017) present an R package for nonparametric boundary regression and provide an overview of existing approaches. Their goal is rather to estimate the boundary of a bivariate distribution than to estimate the boundaries of a time series.…”

Productivity and Efficiency Analysis Software: An Exploratory Bibliographical Survey of the Options

“…These queries lead to a wider set of results due to Google Scholar's extensive capacity to find out documents throughout Internet servers and a wider variety of document sources and types. The attempt to increase the precision of results for geographic (Daouia and Laurent, 2015); -Nonparaeff (Oh and Suh, 2013); -npsf (Badunenko et al, 2017); -Productivity (Dakpo et al, 2016); -semsfa (Ferrara and Vidoli, 2015); -SFA (Straub, 2015); -spfrontier (Pavlyuk, 2016); -SSFA (Fusco and Vidoli, 2015); -TFDEA (Shott and Lim, 2015); -rDEA (Simm and Besstremyannaya, 2016); -DJL (Lim, 2016 Since the submission, we have found the following additional R packages: -Compind (Vidoli and Fusco, 2018); -MultiplierDEA (Puthanpura, 2018); -npbr (Daouia et al, 2017); -sfadv (Desjeux, 2017).…”