Dear all,
Here is a small example : -
> model <- aov(breaks ~ wool * tension, data = warpbreaks)
> summary.lm(model)
Call:
aov(formula = breaks ~ wool * tension, data = warpbreaks)
Residuals:
Min 1Q Median 3Q Max
-19.5556 -6.8889 -0.6667 7.1944 25.4444
Coefficients:
Estimate Std. Error t value Pr(>|t|)
(Intercept) 44.556 3.647 12.218 2.43e-16 ***
woolB -16.333 5.157 -3.167 0.002677 **
tensionM -20.556 5.157 -3.986 0.000228 ***
tensionH -20.000 5.157 -3.878 0.000320 ***
woolB:tensionM 21.111 7.294 2.895 0.005698 **
woolB:tensionH 10.556 7.294 1.447 0.154327
---
Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
Residual standard error: 10.94 on 48 degrees of freedom
Multiple R-squared: 0.3778, Adjusted R-squared: 0.3129
F-statistic: 5.828 on 5 and 48 DF, p-value: 0.0002772
> model.tables(model,"e")
Tables of effects
wool
wool
A B
2.8889 -2.8889
tension
tension
L M H
8.241 -1.759 -6.481
wool:tension
tension
wool L M H
A 5.278 -5.278 0.000
B -5.278 5.278 0.000
> model.tables(model,"m")
Tables of means
Grand mean
28.14815
wool
wool
A B
31.037 25.259
tension
tension
L M H
36.39 26.39 21.67
wool:tension
tension
wool L M H
A 44.56 24.00 24.56
B 28.22 28.78 18.78
>
I don't follow the output of summary.lm. I understand the output of
model.tables for effects and means. For instance what does 44.556 represent
? Is it the grand average ? The grand mean is 28.14815. Can someone help me
understand the output of summary.lm ?
Best Regards,
Ashim
[[alternative HTML version deleted]]
______________________________________________
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
