Cultivation {SASmixed}

Bacterial innoculation applied to grass cultivars

Description

The Cultivation data frame has 24 rows and 4 columns of data from an experiment on the effect on dry weight yield of three bacterial inoculation treatments applied to two grass cultivars.

Format

This data frame contains the following columns:

Block

a factor with levels 1 to 4

Cult

the cultivar factor with levels a and b

Inoc

the innoculant factor with levels con, dea and liv

drywt

a numeric vector of dry weight yields

Source

Littell, R. C., Milliken, G. A., Stroup, W. W., and Wolfinger, R. D. (1996), SAS System for Mixed Models, SAS Institute (Data Set 2.2(a)).

Littel, R. C., Freund, R. J., and Spector, P. C. (1991), SAS System for Linear Models, Third Ed., SAS Institute.

Examples

str(Cultivation)
xtabs(~Block+Cult, Cultivation)
if (require("lme4", quietly = TRUE, character = TRUE)) {
  options(contrasts = c(unordered = "contr.SAS", ordered = "contr.poly"))
  ## compare with Output 2.10, page 58
  print(fm1Cult <- lmer(drywt ~ Inoc * Cult + (1|Block) + (1|Cult),
                          Cultivation))
  print(anova(fm1Cult))
  print(fm2Cult <- lmer(drywt ~ Inoc + Cult + (1|Block) + (1|Cult),
                          Cultivation))
  print(anova(fm2Cult))
  print(fm3Cult <- lmer(drywt ~ Inoc + (1|Block) + (1|Cult), Cultivation))
  print(anova(fm3Cult))
}