pdf("lacrosse.pdf")

lacrosse1 <- read.fwf("C:\\data\\lacrosse.dat", width=c(8,8,14),
col.names=c("brand", "side", "gadd"))

lacrosse1

fbrand <- factor(lacrosse1$brand, levels=1:4)
levels(fbrand) <- c("SHC", "SCHAF", "SCHUL", "BUL")

fside <- factor(lacrosse1$side, levels=1:2)
levels(fside) <- c("Front", "Back")

lacrosse <- data.frame(lacrosse1, fbrand, fside)

lacrosse

attach(lacrosse)

tapply(gadd, fbrand, mean) # marginal mean for brand

tapply(gadd, fside, mean)  # marginal mean for side

tapply(gadd, list(fbrand,fside), mean) # cell means

tapply(gadd, list(fbrand,fside), sd)   # cell SDs

lacrosse1.aov <- anova(lm(gadd ~ fbrand*fside))

lacrosse1.aov


dev.off()