temp <- c(130,160,130,160,145,145,145,145) pres <- c(325,325,475,475,400,400,400,400) x1 <- (temp-145)/15 x2 <- (pres-400)/75 pctconv <- c(8,24,16,32,21,23,20,24) x1_a <- x1[1:4] x2_a <- x2[1:4] pctconv_a <- pctconv[1:4] conv.mod1a <- aov(pctconv_a ~ x1_a + x2_a) anova(conv.mod1a) summary.lm(conv.mod1a) conv.mod2a <- aov(pctconv_a ~ x1_a + x2_a + I(x1_a*x2_a)) anova(conv.mod2a) summary.lm(conv.mod2a) conv.mod1 <- aov(pctconv ~ x1 + x2) anova(conv.mod1) summary.lm(conv.mod1) conv.mod2 <- aov(pctconv ~ x1 + x2 + I(x1^2) + I(x2^2) + I(x1*x2)) anova(conv.mod2) summary.lm(conv.mod2)