BIB {SASmixed}R Documentation

Data from a balanced incomplete block design

Description

The BIB data frame has 24 rows and 5 columns.

Format

This data frame contains the following columns:

Block
an ordered factor with levels 1 < 2 < 3 < 8 < 5 < 4 < 6 < 7
Treatment
a treatment factor with levels 1 to 4.
y
a numeric vector representing the response
x
a numeric vector representing the covariate
Grp
a factor with levels 13 and 24

Details

These appear to be constructed data.

Source

Littel, R. C., Milliken, G. A., Stroup, W. W., and Wolfinger, R. D. (1996), SAS System for Mixed Models, SAS Institute (Data Set 5.4).

Examples

library(SASmixed)
data(BIB)
options(
  contrasts = c(unordered = "contr.SAS", ordered = "contr.poly"))
coplot(y ~ x | Block, data = BIB, show = FALSE)
fm1BIB <- lme(y ~ Treatment * x, data = BIB, random = ~ 1 | Block)
summary(fm1BIB)   # compare with Output 5.7, p. 188
VarCorr(fm1BIB)
anova(fm1BIB)     # strong evidence of different slopes
fm2BIB <- lme(y ~ Treatment + x : Grp, data = BIB,
              random = ~ 1 | Block)
summary(fm2BIB)   # compare with Output 5.9, p. 193
VarCorr(fm2BIB)
anova(fm2BIB)