Data which show the effect of two soporific drugs (increase in hours of sleep compared to control) on 10 patients.
sleep
A data frame with 20 observations on 3 variables.
[, 1] | extra | numeric | increase in hours of sleep |
[, 2] | group | factor | drug given |
The group
variable name may be misleading about the data:
They represent measurements on 10 persons, not in groups.
Scheff<U+00E9>, Henry (1959) The Analysis of Variance. New York, NY: Wiley.
# NOT RUN { require(stats) ## Student's paired t-test with(sleep, t.test(extra[group == 1], extra[group == 2], paired = TRUE)) ## The sleep *prolongations* sleep1 <- with(sleep, extra[group == 2] - extra[group == 1]) summary(sleep1) stripchart(sleep1, method = "stack", xlab = "hours", main = "Sleep prolongation (n = 10)") boxplot(sleep1, horizontal = TRUE, add = TRUE, at = .6, pars = list(boxwex = 0.5, staplewex = 0.25)) # }