SASmixed (version 0.1-7)

Semi2: Oxide layer thicknesses on semiconductors

Description

The Semi2 data frame has 72 rows and 5 columns.

source

Littel, R. C., Milliken, G. A., Stroup, W. W., and Wolfinger, R. D. (1996), SAS System for Mixed Models, SAS Institute (Data Set 4.4).

Examples

options(
  contrasts = c(unordered = "contr.SAS", ordered = "contr.poly"))
data(Semi2)
formula(Semi2)
fm1Semi2 <- lme( Thickness ~ 1, data = Semi2,
   random = ~ 1 | Lot/Wafer )
summary( fm1Semi2 )       # compare with output 4.13, p. 156
VarCorr( fm1Semi2 )
anova( fm1Semi2 )
fm2Semi2 <- update( fm1Semi2, Thickness ~ Source )
summary( fm2Semi2 )       # compare with output 4.15, p. 159
VarCorr( fm2Semi2 )
fm3Semi2 <- update( fm2Semi2, 
   random = list(Lot = pdDiag( ~ Source - 1 ), Wafer = ~ 1 ) )
summary( fm3Semi2 )       # compare with output 4.17, p. 163
VarCorr( fm3Semi2 )