chemreac {EngrExpt}

Yield of a chemical reaction

Description

The yield of a chemical reaction was determined in a replicated 2^3 factorial design.

Format

A data frame with 16 observations on the following 4 variables.

temp

temperature in degrees C - an ordered factor with levels 120 < 140

cat

catalyst - a factor with levels A and B

time

time reaction was run, in minutes - an ordered factor with levels 10 < 30

yield

yield of the reaction

Examples

str(chemreac)
dotplot(temp ~ yield | time, chemreac, groups = cat,
        strip = FALSE, strip.left = TRUE, type = c("p", "a"), layout = c(1,2),
        auto.key = list(space = "right", title = "Catalyst", lines = TRUE))
summary(fm1 <- lm(yield ~ (time + temp + cat)^3, chemreac))
summary(fm2 <- lm(yield ~ time * temp + cat, chemreac))