cuckoos                 package:DAAG                 R Documentation

_C_u_c_k_o_o _E_g_g_s _D_a_t_a

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

     Length and breadth measurements of 120 eggs lain in the nests of
     six  different species of host bird.

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

     cuckoos

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

     This data frame contains the following columns:

     _l_e_n_g_t_h the egg lengths in millimeters

     _b_r_e_a_d_t_h the egg breadths in millimeters

     _s_p_e_c_i_e_s a factor with levels 'hedge.sparrow',  'meadow.pipit', 
          'pied.wagtail',  'robin',  'tree.pipit',  'wren'  

     _i_d a numeric vector

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

     Latter, O.H. (1902). The eggs of Cuculus canorus. An Inquiry into
     the dimensions of the cuckoo's egg and the relation of the
     variations to the size of the eggs of the foster-parent, with
     notes on coloration, &c. Biometrika i, 164.

_R_e_f_e_r_e_n_c_e_s:

     Tippett, L.H.C. 1931: "The Methods of Statistics". Williams &
     Norgate,  London.

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

      
     print("Strip and Boxplots - Example 2.1.2")

     attach(cuckoos)
     oldpar <- par(las = 2) # labels at right angle to axis.
     stripchart(length ~ species) 
     boxplot(split(cuckoos$length, cuckoos$species),
              xlab="Length of egg", horizontal=TRUE)
     detach(cuckoos)
     par(oldpar)
     pause()

     print("Summaries - Example 2.2.2")
     sapply(split(cuckoos$length, cuckoos$species), sd)
     pause()

     print("Example 4.1.4")
     wren <- split(cuckoos$length, cuckoos$species)$wren
     median(wren)
     n <- length(wren)
     sqrt(pi/2)*sd(wren)/sqrt(n)  # this s.e. computation assumes normality

