VisualAcuity {vcd} | R Documentation

## Visual Acuity in Left and Right Eyes

### Description

Data from Kendall & Stuart (1961) on unaided vision among 3,242 men and 7,477 women, all aged 30-39 and employed in the U.K. Royal Ordnance factories 1943-1946.

### Usage

    data(VisualAcuity)

### Format

A data frame with 32 observations and 4 variables.

Freq
  frequency of visual acuity measurements.
right
  visual acuity on right eye.
left
  visual acuity on left eye.
gender
  factor indicating gender of patient.

### Source

M. Friendly (2000), Visualizing Categorical Data: http://euclid.psych.yorku.ca/ftp/sas/vcd/catdata/vision.sas

### References

M. G. Kendall & A. Stuart (1961), The Advanced Theory of Statistics, Vol. 2. Griffin, London.

M. Friendly (2000), Visualizing Categorical Data. SAS Institute, Cary, NC.

### Examples

    data(VisualAcuity)
    structable(~ gender + left + right, data = VisualAcuity)

[Package vcd version 0.9-6 Index]