Semi2 {SASmixed}R Documentation

Oxide layer thicknesses on semiconductors

Description

The Semi2 data frame has 72 rows and 5 columns.

Format

This data frame contains the following columns:

Source
a factor with levels 1 and 2
Lot
a factor with levels 1 to 8
Wafer
a factor with levels 1 to 3
Site
a factor with levels 1 to 3
Thickness
a numeric vector

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"))
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.

[Package SASmixed version 0.3-2 Index]