Industrial Waste Data Set

Description

Industrial waste output in a manufactoring plant.

Usage

data("waste")

Format

This data frame contains the following variables

temp

temperature, a factor at three levels: low, medium, high.

envir

environment, a factor at five levels: env1 ... env5.

waste

response variable: waste output in a manufacturing plant.

Details

The data are from an experiment designed to study the effect of temperature (temp) and environment (envir) on waste output in a manufactoring plant. Two replicate measurements were taken at each temperature / environment combination. Data were obtained from Westfall, Tobias, Rom, Wolfinger, and Hochberg (1999), page 177.

References

Westfall P. H., Tobias R. D., Rom D., Wolfinger R. D., Hochberg Y. (1999). Multiple Comparisons and Multiple Tests Using the SAS System. SAS Institute Inc., Cary, NC.

Examples

  ### set up two-way ANOVA with interactions
  amod <- aov(waste ~ temp * envir, data=waste)

  ### comparisons of main effects only
  K <- glht(amod, linfct = mcp(temp = "Tukey"))$linfct
  K
  glht(amod, K)

  ### comparisons of means (by averaging interaction effects)
  low <- grep("low:envi", colnames(K))
  med <- grep("medium:envi", colnames(K))
  K[1, low] <- 1 / (length(low) + 1)
  K[2, med] <- 1 / (length(low) + 1)
  K[3, med] <- 1 / (length(low) + 1)
  K[3, low] <- - 1 / (length(low) + 1)
  K
  confint(glht(amod, K))

  ### same as TukeyHSD
  TukeyHSD(amod, "temp")

  ### set up linear hypotheses for all-pairs of both factors
  wht <- glht(amod, linfct = mcp(temp = "Tukey", envir = "Tukey"))

  ### cf. Westfall et al. (1999, page 181)
  summary(wht, test = adjusted("Shaffer"))