coffee <- data.frame( pid = 1:10, pre = c(5, 3, 2, 7, 3, 1, 4, 3, 9, 3), post = c(4, 3, 1, 6, 2, 2, 2, 2, 5, 2)) plot(c(1, 2), c(0, 10), type="n", frame=FALSE, axes=FALSE, xlab="コーヒー飲用", ylab="誤答数") segments(1, coffee$pre, 2, coffee$post) axis(1, 1:2, c("前", "後")) axis(2, 0:10, 0:10) t.test(coffee$post, coffee$pre, paired=TRUE) # t.test(coffee$post-coffee$pre, mu=0) scoffee <- data.frame( pid = rep(coffee$pid, 2), errors = c(coffee$pre, coffee$post), setting = factor(c(rep(1, 10), rep(2, 10)), labels=c("pre", "post"))) scoffee2 <- stack(list(pre=coffee$pre, post=coffee$post)) library(car) colnames(coffee) <- c("pid", "t.0", "t.1") # rename pre as t.0 and post as t.1 scoffee3 <- reshape(coffee, direction="long", idvar="pid", varying=c("t.0","t.1")) coffee3 <- reshape(scoffee3, direction="wide") # で戻せる stripchart(errors ~ setting, data=scoffee, method="jitter", vert=TRUE, ylim=c(0, 10)) meanerrors <- tapply(scoffee$errors, scoffee$setting, mean) sderrors <- tapply(scoffee$errors, scoffee$setting, sd) igroups <- c(1.1, 2.1) points(igroups, meanerrors, pch=18, cex=2) arrows(igroups, meanerrors-sderrors, igroups, meanerrors+sderrors, angle=90, code=3) t.test(errors ~ setting, data=scoffee) plot(errors ~ setting, data=scoffee) wilcox.test(errors ~ setting, data=scoffee)