skulls {HSAUR} | R Documentation |
Measurements made on Egyptian skulls from five epochs.
data("skulls")
A data frame with 150 observations on the following 5 variables.
epoch
c4000BC
c3300BC
,
c1850BC
, c200BC
, and cAD150
,
where the years are only given approximately, of
course.mb
bh
bl
nh
The question is whether the measurements change over time. Non-constant measurements of the skulls over time would indicate interbreeding with immigrant populations.
D. J. Hand, F. Daly, A. D. Lunn, K. J. McConway and E. Ostrowski (1994). A Handbook of Small Datasets, Chapman and Hall/CRC, London.
data("skulls", package = "HSAUR") means <- tapply(1:nrow(skulls), skulls$epoch, function(i) apply(skulls[i,colnames(skulls)[-1]], 2, mean)) means <- matrix(unlist(means), nrow = length(means), byrow = TRUE) colnames(means) <- colnames(skulls)[-1] rownames(means) <- levels(skulls$epoch) pairs(means, panel = function(x, y) { text(x, y, levels(skulls$epoch)) })