Goodness-of-Fit Tests for Ordinal Regression Models

Provides goodness-of-fit tests for ordinal regression models, including the Fagerland-Hosmer ordinal test, reproducing same output as 'Stata'. Supports polr(), vglm(), and binary glm() models. See Fagerland and Hosmer (2013) and Fagerland and Hosmer (2017) for details.