These two R packages are hosted on nCal: Nonlinear Calibration and prc: Paired Response Curve.
In addition, here is a FAQ focused on installation and graphical user interface (GUI) of nCal.
References
The R package krm provides a way to fit regression model with protein sequence covariates through a kernel-based random effect model.
References
rBHP is a general clustering/mixture modeling algorithm that is based on randomized Bottom-up Hierarchical clustering Pruned (rBHP) splits.
cHMM is a mixture model based clustering method for identifying protein subfamily, and it uses rBHP as part of the inference machinery.
Brief Guide
References
The R chngpt package is hosted on chngpt: Estimation and Hypothesis Testing for Threshold Regression, and more up-to-date versions may be found here.
References