barley                package:lattice                R Documentation

_Y_i_e_l_d _d_a_t_a _f_r_o_m _a _M_i_n_n_e_s_o_t_a _b_a_r_l_e_y _t_r_i_a_l

_D_e_s_c_r_i_p_t_i_o_n:

     Total yield in bushels per acre for 10 varieties at 6 sites in
     each of two years.

_U_s_a_g_e:

     barley

_F_o_r_m_a_t:

     A data frame with 120 observations on the following 4 variables.

     _y_i_e_l_d Yield (averaged across three blocks) in bushels/acre.

     _v_a_r_i_e_t_y Factor with levels ''Svansota'', ''No. 462'',
          ''Manchuria'', ''No. 475'', ''Velvet'', ''Peatland'',
          ''Glabron'', ''No. 457'', ''Wisconsin No. 38'', ''Trebi''.

     _y_e_a_r Factor with levels '1932', '1931'

     _s_i_t_e Factor with 6 levels:  ''Grand Rapids'', ''Duluth'',
          ''University Farm'', ''Morris'', ''Crookston'', ''Waseca''

_D_e_t_a_i_l_s:

     These data are yields in bushels per acre, of 10 varieties of
     barley grown in 1/40 acre plots at University Farm, St. Paul, and
     at the five branch experiment stations located at Waseca, Morris,
     Crookston, Grand Rapids, and Duluth (all in Minnesota).  The
     varieties were grown in three randomized blocks at each of the six
      stations during 1931 and 1932, different land being used each
     year of the test.

     Immer et al. (1934) present the data for each
     Year*Site*Variety*Block. The data here is the average yield across
     the three blocks.

     Immer et al. (1934) refer (once) to the experiment as being
     conducted in 1930 and 1931, then later refer to it (repeatedly) as
     being conducted in 1931 and 1932.  Later authors have continued
     the confusion.

     Cleveland (1993) suggests that the data for the Morris site may
     have had the years switched.

_A_u_t_h_o_r(_s):

     Documentation contributed by Kevin Wright.

_S_o_u_r_c_e:

     Immer, R. F., H. K. Hayes, and LeRoy Powers. (1934).  Statistical
     Determination of Barley Varietal Adaptation.  _Journal of the
     American Society of Agronomy_, *26*, 403-419.

_R_e_f_e_r_e_n_c_e_s:

     Cleveland, William S. (1993). _Visualizing Data_.  Hobart Press,
     Summit, New Jersey.

     Fisher, R. A. (1971). _The Design of Experiments_.  Hafner, New
     York, 9th edition.

_S_e_e _A_l_s_o:

     'immer' in the MASS package for data from the same experiment 
     (expressed as total yield for 3 blocks) for a subset of varieties.

_E_x_a_m_p_l_e_s:

     # Graphic suggesting the Morris data switched the years 1931 and 1932
     # Figure 1.1 from Cleveland
     dotplot(variety ~ yield | site, data = barley, groups = year,
             key = simpleKey(levels(barley$year), space = "right"),
             xlab = "Barley Yield (bushels/acre) ",
             aspect=0.5, layout = c(1,6), ylab=NULL)

