| Trucks {vcd} | R Documentation |
Truck Accidents Data
Description
Data from a study in England in two periods from November 1969 to October 1971 and November 1971 to October 1973. A new compulsory safety measure for trucks was introduced in October 1971. Therefore, the question is whether the safety measure had an effect on the number of accidents and on the point of collision on the truck.
Usage
data("Trucks")
Format
A data frame with 24 observations on 5 variables.
- Freq
frequency of accidents involving trucks.
- period
factor indicating time period (before, after) 1971-11-01.
- collision
factor indicating whether the collision was in the back or forward (including the front and the sides) of the truck (back, forward).
- parked
factor indicating whether the truck was parked (yes, no).
- light
factor indicating light conditions: day light (daylight), night on an illuminated road (night, illuminate), night on a dark road (night, dark).
Source
E. B. Andersen (1991), The Statistical Analysis of Categorical Data, Table 6.8.
References
E. B. Andersen (1991), The Statistical Analysis of Categorical Data. 2nd edition. Springer-Verlag, Berlin.
Examples
library(MASS)
data("Trucks")
tab <- xtabs(Freq ~ period + collision + light + parked, data = Trucks)
loglm(~ (collision + period) * parked * light, data = tab)
doubledecker(collision ~ parked + light + period, data = tab)
cotabplot(tab, panel = cotab_coindep)