Semiconductor            package:SASmixed            R Documentation

_S_e_m_i_c_o_n_d_u_c_t_o_r _s_p_l_i_t-_p_l_o_t _e_x_p_e_r_i_m_e_n_t

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

     The 'Semiconductor' data frame has 48 rows and 5 columns.

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

     This data frame contains the following columns:

     _r_e_s_i_s_t_a_n_c_e a numeric vector

     _E_T a factor with levels '1' to '4' representing etch time.

     _W_a_f_e_r a factor with levels '1' to '3' 

     _p_o_s_i_t_i_o_n a factor with levels '1' to '4' 

     _G_r_p an ordered factor with levels '1/1' < '1/2' < '1/3' < '2/1' <
          '2/2' < '2/3' < '3/1' < '3/2' < '3/3' < '4/1' < '4/2' < '4/3'

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

_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(b)).

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

     str(Semiconductor)
     if (require("lme4", quietly = TRUE, character = TRUE)) {
       options(contrasts = c(unordered = "contr.SAS", ordered = "contr.poly"))
       print(fm1Semi <- lmer(resistance ~ ET * position + (1|Grp), Semiconductor))
       print(anova(fm1Semi))
       print((fm2Semi <- lmer(resistance ~ ET + position + (1|Grp), Semiconductor)))
       print(anova(fm2Semi))
     }

