x1 <- rep(c(1,0,0,1/2,1/2,0,1/3),each=2) x2 <- rep(c(0,1,0,1/2,0,1/2,1/3),each=2) x3 <- rep(c(0,0,1,0,1/2,1/2,1/3),each=2) trt <- rep(1:7,each=2) trt <- factor(trt) y <- c(106.6,105.0,83.3,81.4,99.4,91.4,94.1, 91.4,101.9,98.0,92.3,86.5,96.3,91.7) gasblend.mod1 <- aov(y ~ x1 + x2 + x3 + I(x1*x2) + I(x1*x3) + I(x2*x3) + trt) anova(gasblend.mod1) gasblend.mod2 <- aov(y ~ x1 + x2 + x3 + trt) anova(gasblend.mod2) gasblend.mod3 <- aov(y ~ trt) anova(gasblend.mod3) gasblend.mod4 <- aov(y ~ -1 + x1 + x2 + x3) summary.lm(gasblend.mod4) gasblend.mod5 <- aov(y ~ -1 + x1 + x2 + x3 + I(x1*x2) + I(x1*x3) + I(x2*x3)) summary.lm(gasblend.mod5)