Rail {nlme} | R Documentation

## 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.''

### Source

Pinheiro, J. C. and Bates, D. M. (2000), Mixed-Effects Models in S and S-PLUS, Springer, New York. (Appendix A.26)

Devore, J. L. (2000), Probability and Statistics for Engineering and the Sciences (5th ed), Duxbury, Boston, MA.

### Examples

    data(Rail)

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