morley               package:datasets               R Documentation

Michaelson-Morley Speed of Light Data

Description:

     The classical data of Michaelson and Morley on the speed of light.
     The data consists of five experiments, each consisting of 20
     consecutive 'runs'.  The response is the speed of light
     measurement, suitably coded.

Usage:

     morley

Format:

     A data frame contains the following components:

     'Expt' The experiment number, from 1 to 5.

     'Run' The run number within each experiment.

     'Speed' Speed-of-light measurement.

Details:

     The data is here viewed as a randomized block experiment with
     'experiment' and 'run' as the factors.  'run' may also be
     considered a quantitative variate to account for linear (or
     polynomial) changes in the measurement over the course of a single
     experiment.

Source:

     A. J. Weekes (1986) _A Genstat Primer_. London: Edward Arnold.

Examples:

     require(stats); require(graphics)
     morley$Expt <- factor(morley$Expt)
     morley$Run <- factor(morley$Run)

     xtabs(~ Expt + Run, data = morley)# 5 x 20 balanced (two-way)
     plot(Speed ~ Expt, data = morley,
          main = "Speed of Light Data", xlab = "Experiment No.")
     fm <- aov(Speed ~ Run + Expt, data = morley)
     summary(fm)
     fm0 <- update(fm, . ~ . - Run)
     anova(fm0, fm)

