The goal of sclr is to fit the scaled logit model from Dunning (2006) using the maximum likelihood method. The package website contains all documentation, vignettes and version history.


Install the CRAN version with

Or the development version from GitHub with:


The model is logistic regression with an added parameter for the top asymptote. For model specification, log likelihood, scores and second derivatives see the math vignette. Documentation of the main fitting function ?sclr has details on how the model is fit.


Dunning AJ (2006). “A model for immunological correlates of protection.” Statistics in Medicine, 25(9), 1485-1497. doi: 10.1002/sim.2282.