MEMSS (version 0.9-3)

Rail: Evaluation of Stress in Railway Rails

Description

The Rail data frame has 18 rows and 2 columns.

Format

This data frame contains the following columns:

Rail

an ordered factor identifying the rail on which the measurement was made.

travel

a numeric vector giving the travel time for ultrasonic head-waves in the rail (nanoseconds). The value given is the original travel time minus 36,100 nanoseconds.

Details

Devore (2000, Example 10.10, p. 427) cites data from an article in Materials Evaluation on ``a study of travel time for a certain type of wave that results from longitudinal stress of rails used for railroad track.''

Examples

# NOT RUN {
str(Rail)
(fm1 <- lmer(travel ~ 1 | Rail, Rail))
# }