A small count data set
involving 414 machinists from a three months study,
of accidents around the end of WWI.
Usage
data(machinists)
Format
A data frame with the following variables.
accidents
The number of accidents
ofreq
Observed frequency, i.e., the number of machinists
with that many accidents
Details
The data was collected over a period of three months.
There were 414 machinists in total.
Also, there were data collected over six months, but it
is not given here.
Source
Incidence of Industrial Accidents.
Report No. 4 (Industrial Fatigue Research Board),
Stationery Office, London, 1919.
References
Greenwood, M. and Yule, G. U. (1920).
An Inquiry into the Nature of Frequency Distributions
Representative of Multiple Happenings with Particular
Reference to the Occurrence of Multiple Attacks of Disease
or of Repeated Accidents.
Journal of the Royal Statistical Society,
83, 255–279.
See Also
negbinomial,
poissonff.
Examples
machinists
mean(with(machinists, rep(accidents, times = ofreq)))
var(with(machinists, rep(accidents, times = ofreq)))
## Not run: barplot(with(machinists, ofreq),
names.arg = as.character(with(machinists, accidents)),
main = "Machinists accidents",
col = "lightblue", las = 1,
ylab = "Frequency", xlab = "accidents")
## End(Not run)