Npregfast: An R package for nonparametric estimation and inference in life sciences

We present the r npregfast package via some applications involved with the study of living organisms. the package implements nonparametric estimation procedures in regression models with or without factor-by-curve interactions. the main feature of the package is its ability to perform inference regarding these models. namely,the implementation of different procedures to test features of the estimated regression curves: on the one hand,the comparisons between curves which may vary across groups defined by levels of a categorical variable or factor; on the other hand,the comparisons of some critical points of the curve (e.g.,maxima,minima or inflection points),studying for this purpose the derivatives of the curve. © 2017,american statistical association. all rights reserved.