skulls {HSAUR3}

Egyptian Skulls

Description

Measurements made on Egyptian skulls from five epochs.

Usage

data("skulls")

Format

A data frame with 150 observations on the following 5 variables.

epoch

the epoch the skull as assigned to, a factor with levels c4000BC c3300BC, c1850BC, c200BC, and cAD150, where the years are only given approximately, of course.

mb

maximum breaths of the skull.

bh

basibregmatic heights of the skull.

bl

basialiveolar length of the skull.

nh

nasal heights of the skull.

Details

The question is whether the measurements change over time. Non-constant measurements of the skulls over time would indicate interbreeding with immigrant populations.

Source

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.

Examples

  data("skulls", package = "HSAUR3")
  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))
      })