pneumo {VGAM} | R Documentation

## Pneumoconiosis in Coalminers Data

### 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)

### Format

This data frame contains the following columns:

exposure.time
  a numeric vector, in years
normal
  a numeric vector, counts
mild
  a numeric vector, counts
severe
  a numeric vector, counts

### Details

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

### Source

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

### References

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

### Examples

    # 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)

[Package VGAM version 0.7-9 Index]