> tapply(h2o,list(salinity,days),mean) 14 21 28 0 2.75 5.35 12.80 6 4.10 6.55 10.20 12 3.10 5.20 7.95 > > barley.mod1 <- aov(h2o ~ salinity + days + salinity:days) > summary(barley.mod1) Df Sum Sq Mean Sq F value Pr(>F) salinity 2 9.508 4.754 8.5229 0.008381 ** days 2 151.988 75.994 136.2440 1.869e-07 *** salinity:days 4 18.209 4.552 8.1614 0.004591 ** Residuals 9 5.020 0.558 --- Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1 > > summary(barley.mod1,split=list(salinity=list(linear=1,quadratic=2))) Df Sum Sq Mean Sq F value Pr(>F) salinity 2 9.508 4.754 8.5229 0.008381 ** salinity: linear 1 7.208 7.208 12.9218 0.005796 ** salinity: quadratic 1 2.300 2.300 4.1240 0.072844 . days 2 151.988 75.994 136.2440 1.869e-07 *** salinity:days 4 18.209 4.552 8.1614 0.004591 ** salinity:days: linear 2 16.460 8.230 14.7550 0.001442 ** salinity:days: quadratic 2 1.749 0.874 1.5677 0.260518 Residuals 9 5.020 0.558 --- Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1 > summary(barley.mod1,split=list(days=list(linear=1,quadratic=2))) Df Sum Sq Mean Sq F value Pr(>F) salinity 2 9.508 4.754 8.5229 0.008381 ** days 2 151.988 75.994 136.2440 1.869e-07 *** days: linear 1 147.000 147.000 263.5458 5.667e-08 *** days: quadratic 1 4.988 4.988 8.9422 0.015192 * salinity:days 4 18.209 4.552 8.1614 0.004591 ** salinity:days: linear 2 14.735 7.367 13.2087 0.002102 ** salinity:days: quadratic 2 3.474 1.737 3.1140 0.093797 . Residuals 9 5.020 0.558 --- Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1 >