It comes with a very powerful optimiser for common models such as logistic function (or Hill function). Compared with the native R implementations using the
nlsfunction and self start models such as
drcpackage is far more reliable and robust: both initial parameter estimation and optimisation run without errors due to singularity : at least in the ~3,000 datasets that I tried, on which
nlsfailed as much as 600 cases despite of manually setting starting parameters with educated guess.
I still have to understand how the package achieves such good performance. However I am already very glad that we have finally a robust and reliable optimiser for curve fitting, which is a common task in computational biology and bioinformatics.
Figure: a 4-parameter logistic fit done and plotted with