VGAM (version 0.7-8)

pneumo: Pneumoconiosis amongst a group of coalminers

Description

The pneumo data frame has 8 rows and 4 columns. Exposure time is explanatory, and there are 3 ordinal response variables.

Usage

data(pneumo)

source

Ashford, J.R., 1959. An approach to the analysis of data for semi-quantal responses in biological assay. Biometrics, 15, 573--581.

Details

These were collected from coalface workers. In the original data set, the two most severe categories were combined.

References

McCullagh, P. and Nelder, J. A. (1989) Generalized Linear Models, 2nd ed. London: Chapman & Hall.

Examples

data(pneumo)

# Fit the proportional odds model, p.179, in McCullagh and Nelder (1989) 
pneumo = transform(pneumo, let=log(exposure.time))
vglm(cbind(normal,mild,severe) ~ let, 
     cumulative(parallel=TRUE, reverse=TRUE), pneumo)