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:

     library(SASmixed)
     options(
       contrasts = c(unordered = "contr.SAS", ordered = "contr.poly"))
     data(Semiconductor)
     formula( Semiconductor )
     names( Semiconductor )
     fm1Semi <- lme( resistance ~ ET * position,
                      data = Semiconductor,
                      random = ~ 1 | Grp)
     summary( fm1Semi )
     VarCorr( fm1Semi )
     anova( fm1Semi )
     fm2Semi <- update( fm1Semi, resistance ~ ET + position )
     anova(fm2Semi)

