An automated approach to Litchfield and Wilcoxon's evaluation of dose–effect experiments using the R package LW1949

Abstract

The authors developed a package, LW1949, for use with the statistical software R to automatically carry out the manual steps of Litchfield and Wilcoxon's method of evaluating dose–effect experiments. The LW1949 package consistently finds the best fitting dose–effect relation by minimizing the chi‐squared statistic of the observed and expected number of affected individuals and substantially speeds up the line‐fitting process and other calculations that Litchfield and Wilcoxon originally carried out by hand. Environ Toxicol Chem 2016;35:3058–3061. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US Government work and, as such, is in the public domain in the United States of America.