Cultivation             package:SASmixed             R Documentation

_B_a_c_t_e_r_i_a_l _i_n_n_o_c_u_l_a_t_i_o_n _a_p_p_l_i_e_d _t_o _g_r_a_s_s _c_u_l_t_i_v_a_r_s

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

     The 'Cultivation' data frame has 24 rows and 4 columns of data
     from an experiment on the effect on dry weight yield of three
     bacterial inoculation treatments applied to two grass cultivars.

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

     This data frame contains the following columns:

     _B_l_o_c_k a factor with levels '1' to '4'

     _C_u_l_t the cultivar factor with levels 'a' and 'b'

     _I_n_o_c the innoculant factor with levels 'con', 'dea' and 'liv'

     _d_r_y_w_t a numeric vector of dry weight yields

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

     Littel, R. C., Milliken, G. A., Stroup, W. W., and Wolfinger, R.
     D. (1996), _SAS System for Mixed Models_, SAS Institute (Data Set
     2.2(a)).

     Littel, R. C., Freund, R. J., and Spector, P. C. (1991), _SAS
     System for Linear Models, Third Ed._, SAS Institute.

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

     str(Cultivation)
     xtabs(~Block+Cult, Cultivation)
     if (require("lme4", quietly = TRUE, character = TRUE)) {
       options(contrasts = c(unordered = "contr.SAS", ordered = "contr.poly"))
       ## compare with Output 2.10, page 58
       print(fm1Cult <- lmer(drywt ~ Inoc * Cult + (1|Block) + (1|Cult),
                               Cultivation))
       print(anova(fm1Cult))
       print(fm2Cult <- lmer(drywt ~ Inoc + Cult + (1|Block) + (1|Cult),
                               Cultivation))
       print(anova(fm2Cult))
       print(fm3Cult <- lmer(drywt ~ Inoc + (1|Block) + (1|Cult), Cultivation))
       print(anova(fm3Cult))
     }

