The package drc

drc is an add-on package to R.

The package provides functionality for estimation in and hypothesis tests of multiple non-linear regression models.

The focus is on non-linear models used to describe data from bioassays, that is dose response curves.

Common models for bioassays are integrated into the package for convenient use, but arbitrary multiple non-linear regression models can be fitted.
It requires specification of the non-linear function and an appropriate self starter function to supply initial parameter values.


In more detail, the package contains functionality for

• specification of a single model for multiple dose-response experiments,
  
  
• model specification for each parameter via a model formula,
  
  
• comparison of arbitrary parameters across bioassays,
  
  
• ANOVA lack of fit test and test for model reduction,
  
  
• Box-Cox transformation (transform-both-sides approach),
  
  
• several standard functions are built-in with self-starter facility,
  
  
• calculation of arbitrary effective dosages and selectivity indices for built-in function.
  
  
  

• more standard built-in functions,
  
  
• robust estimation,
  
  
• handling models with correlation structure.