pdf("oehemp4_3.pdf") leaflet <- matrix(c( 1, 140, 1, 138, 1, 140, 1, 138, 1, 142, 2, 140, 2, 150, 2, 120, 2, 128, 2, 130, 3, 118, 3, 130, 3, 128, 3, 118, 3, 118), ncol=2, byrow=T) angle <- leaflet[,2] delay <- leaflet[,1] delayf <- C(factor(delay),contr=contr.poly,scores=sort(unique(delay))) delay angle delayf tapply(angle, delayf, mean) tapply(angle, delayf, sd) contr.poly(3) angle.aov <- aov(angle ~ delayf) summary(angle.aov, split=list(delayf=list(linear=1,quadratic=2))) angle2.aov <- aov(angle ~ delay + I(delay^2)) summary(angle2.aov) dev.off()