# Re: [R] How to extract numbers from ANOVA tables?

From: John Fox <jfox_at_mcmaster.ca>
Date: Sat, 8 Dec 2007 09:03:26 -0500

Dear Lars,

In addition to looking at the relevant help pages, a nice thing about R is that the objects are there for you to examine. For example:

> mod <- lm(mpg ~ ., data=mtcars)
> av <- anova(mod)

> names(av)

[1] "Df" "Sum Sq" "Mean Sq" "F value" "Pr(>F)"

> str(av)

```Classes 'anova' and 'data.frame':       11 obs. of  5 variables:
\$ Df     : int  1 1 1 1 1 1 1 1 1 1 ...
\$ Sum Sq : num  817.71  37.59   9.37  16.47  77.48 ...
\$ Mean Sq: num  817.71  37.59   9.37  16.47  77.48 ...
```
\$ F value: num 116.42 5.35 1.33 2.34 11.03 ...  \$ Pr(>F) : num 5.03e-10 3.09e-02 2.61e-01 1.41e-01 3.24e-03 ...
• attr(*, "heading")= chr "Analysis of Variance Table\n" "Response: mpg"

Thus, e.g., av\$"Sum Sq" returns the sums of squares:

> av\$"Sum Sq"

[1] 817.7129524 37.5939529 9.3709293 16.4674349 77.4757948 3.9493082  [7] 0.1297687 14.4742372 0.9717105 0.4066688 147.4944300

You could do the same thing with the object returned by summary().

I hope that this helps,
John

John Fox, Professor
Department of Sociology
McMaster University
Hamilton, Ontario
905-525-9140x23604
http://socserv.mcmaster.ca/jfox

> -----Original Message-----
> From: r-help-bounces_at_r-project.org
> [mailto:r-help-bounces_at_r-project.org] On Behalf Of Brinkmann, Lars
> Sent: Saturday, December 08, 2007 4:09 AM
> To: r-help_at_stat.math.ethz.ch
> Subject: [R] How to extract numbers from ANOVA tables?
>
> I need to extract numbers (eg. estimates, standard errors
> etc.) summarized in an ANOVA table or summary() table for
> further calculations. Can somebody help me or refer me to the
> needed resource on the web?
>
> [[alternative HTML version deleted]]
>
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