Cusp-Catastrophe Model Fitting Using Maximum Likelihood
Description
Cobb's maximum likelihood method for cusp-catastrophe modeling
(Grasman, van der Maas, and Wagenmakers (2009) ;
Cobb (1981), Behavioral Science, 26(1), 75-78). Includes a cusp() function for model
fitting, and several utility functions for plotting, and for comparing the
model to linear regression and logistic curve models.