skulls                 package:HSAUR                 R Documentation

_E_g_y_p_t_i_a_n _S_k_u_l_l_s

_D_e_s_c_r_i_p_t_i_o_n:

     Measurements made on Egyptian skulls from five epochs.

_U_s_a_g_e:

     data("skulls")

_F_o_r_m_a_t:

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

     '_e_p_o_c_h' 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.

     '_m_b' maximum breaths of the skull.

     '_b_h' basibregmatic heights of the skull.

     '_b_l' basialiveolar length of the skull.

     '_n_h' nasal heights of the skull.

_D_e_t_a_i_l_s:

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

_S_o_u_r_c_e:

     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.

_E_x_a_m_p_l_e_s:

       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))
           })

