Semi2 {SASmixed} | R Documentation |
The Semi2
data frame has 72 rows and 5 columns.
This data frame contains the following columns:
1
and 2
1
to 8
1
to 3
1
to 3
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).
options(contrasts = c(unordered = "contr.SAS", ordered = "contr.poly")) str(Semi2) xtabs(~Lot + Wafer, Semi2) Semi2$LotWafer <- with(Semi2, Lot:Wafer) fm1Semi2 <- lmer(Thickness ~ 1 + (1|LotWafer) + (1|Lot), Semi2) summary(fm1Semi2) # compare with output 4.13, p. 156 fm2Semi2 <- lmer(Thickness ~ Source + (1|LotWafer) + (1|Lot), Semi2) summary(fm2Semi2) # compare with output 4.15, p. 159 anova(fm2Semi2) Semi2$LotSrc <- with(Semi2, Lot:Source) fm3Semi2 <- lmer(Thickness ~ Source + (1|LotWafer) + (1|LotSrc), Semi2) summary(fm3Semi2) # compare with output 4.17, p. 163 ## This is not the same as the SAS model.