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.

### See Also

`cumulative`.

### 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, propodds, data = pneumo)

[Package VGAM version 1.0-3 Index]