######### Exercise 6.1 set.seed(123321) c1 <- round(rnorm(10, 65, 10), 0) c2 <- round(rnorm(10, 80, 10), 0) n1 <- c1 + 15 + round(rnorm(10, 15, 3), 0) n2 <- c2 + 0 + round(rnorm(10, 15, 3), 0) id <- 1:20 coach <- factor(rep(1:2, each = 10), labels = c("yes", "no")) dat <- data.frame(id, coach, pre = c(c1, c2), post = c(n1, n2)) # ANCOVA method library(car) library(phia) ancova1 <- aov(post ~ coach + pre, data = dat) Anova(ancova1, type = 3) interactionMeans(ancova1, "coach") # Traditional Repeated-measures ANOVA longdat <- dat[,1:2] longdat <- rbind(longdat, longdat) timefac <- factor(rep(c("pre", "post"), each = 20)) score <- c(dat$pre, dat$post) longdat <- data.frame(longdat, timefac, score) library(ez) ezANOVA(data = longdat, dv = score, wid = id, within = .(timefac), between = c("coach")) # MANOVA obj <- lm(cbind(pre, post) ~ coach, data = dat) idata <- data.frame(time = c("pre", "post")) Anova(obj, idata = idata, idesign = ~ time, type = 3) testInteractions(obj, idata = idata, across = "time", fixed = "coach", adjustment = "bonferroni") interactionMeans(obj, idata = idata) plot(interactionMeans(obj, idata = idata)) ######### Homework 6 group <- factor(rep(c("T", "C"), each = 7)) w1 <- c(2722, 3289, 2892, 3175, 3062, 2608, 3402, 3175, 2693, 3232, 2807, 3515, 2835, 3005) w2 <- c(2778, 3289, 2892, 3260, 3118, 2693, 3430, 3147, 2722, 3175, 2835, 3544, 2778, 3033) w3 <- c(2920, 3345, 2863, 3289, 3175, 2722, 3430, 3147, 2778, 3118, 2807, 3600, 2693, 3005) w4 <- c(2948, 3374, 2863, 3345, 3260, 2778, 3487, 3090, 2807, 3090, 2778, 3572, 2665, 3033) dat <- data.frame(group, w1, w2, w3, w4) aggregate(cbind(w1, w2, w3, w4) ~ group, data = dat, FUN = mean) aggregate(cbind(w1, w2, w3, w4) ~ group, data = dat, FUN = sd) library(phia) library(car) manovaout <- lm(cbind(w1, w2, w3, w4) ~ group, data = dat) idata <- data.frame(time = c("w1", "w2", "w3", "w4")) plot(interactionMeans(manovaout, idata = idata)) # ANCOVA ancovaout <- aov(w4 ~ group + w1 + w2 + w3, data = dat) Anova(ancovaout, type = 3) # Traditional Repeated-measures ANOVA groupfac <- rep(group, 4) id <- rep(1:14, 4) timefac <- factor(rep(c("day1", "day2", "day3", "day4"), each = 14)) weight <- c(w1, w2, w3, w4) longdat <- data.frame(groupfac, timefac, id, weight) library(ez) ezANOVA(data = longdat, dv = weight, wid = id, within = .(timefac), between = c("groupfac")) # MANOVA Anova(manovaout, idata = idata, idesign = ~ time, type = 3) testInteractions(manovaout, idata = idata, across = "time", fixed = "group", adjustment = "bonferroni") testInteractions(manovaout, idata = idata, pairwise = "time", fixed = "group", adjustment = "bonferroni") ctr <- poly(1:4, 1) total.ctr <- list(time = ctr) testInteractions(manovaout, idata = idata, custom = total.ctr, fixed = "group", adjustment = "bonferroni")