Data simulated from a probit model with a quadratic trend. The data are
described in Example 2 of Liu and Zhang (2017).
Usage
data(df1)
Arguments
Format
A data frame with 2000 rows and 2 variables.
x The predictor variable.
y The response variable; an ordered factor.
References
Liu, Dungang and Zhang, Heping. Residuals and Diagnostics for Ordinal
Regression Models: A Surrogate Approach.
Journal of the American Statistical Association (accepted).