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
to4
. - y
-
a numeric vector representing the response
- x
-
a numeric vector representing the covariate
- Grp
-
a factor with levels
13
and24
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
str(BIB)
if (require("lattice", quietly = TRUE, character = TRUE)) {
xyplot(y ~ x | Block, BIB, groups = Treatment, type = c("g", "p"),
aspect = "xy", auto.key = list(points = TRUE, space = "right",
lines = FALSE))
}
if (require("lme4", quietly = TRUE, character = TRUE)) {
options(contrasts = c(unordered = "contr.SAS", ordered = "contr.poly"))
## compare with Output 5.7, p. 188
print(fm1BIB <- lmer(y ~ Treatment * x + (1 | Block), BIB))
print(anova(fm1BIB)) # strong evidence of different slopes
## compare with Output 5.9, p. 193
print(fm2BIB <- lmer(y ~ Treatment + x : Grp + (1 | Block), BIB))
print(anova(fm2BIB))
}
[Package SASmixed version 1.0-4 Index]