R help - Aug 2008 - ANOVA tables - storing F values

When I run a summary(anova) I get output for all of the elements (columns)
as these are multiple - single anova results.  Can I store the F values?  I
can't find the attribute of the fitted model attributes(fit) that stores
these F values, and for that matter, P values.

Thanks

-- 
Gareth Campbell
PhD Candidate
The University of Auckland

P +649 815 3670
M +6421 256 3511
E gareth.campbell@esr.cri.nz
gcam032@gmail.com

	[[alternative HTML version deleted]]

Hi,

lets look at an example:
fit <- lm(sr ~ ., data = LifeCycleSavings)
fit.anova <- anova(fit)

you can see the structure from the anova:
str(fit.anova)

Classes ?anova? and 'data.frame':       5 obs. of  5 variables:
 $ Df     : int  1 1 1 1 45
 $ Sum Sq : num  204.1  53.3  12.4  63.1 650.7
 $ Mean Sq: num  204.1  53.3  12.4  63.1  14.5
 $ F value: num  14.116  3.689  0.858  4.360     NA
 $ Pr(>F) : num  0.000492 0.061125 0.359355 0.042471       NA
 - attr(*, "heading")= chr  "Analysis of Variance Table\n"
"Response: sr"


Here you see that you can acces the F values by typing: fit.anova$"F
value"
or by fit.anova[,"F value"]
Use the same method for your p-values.

the other way you mentioned brings you to the same methods:
attributes(fit.anova)

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

$..........


Best regards

Bart
-- 
View this message in context:
http://www.nabble.com/ANOVA-tables---storing-F-values-tp18937255p18939847.html
Sent from the R help mailing list archive at Nabble.com.

You need to store the result of the summary function:
> sfit <- summary(fit)
Then look at the structure of the sfit (or whatever you call it) object
(depending on the fit, it may be different).  You can do this with the
'str' function or the 'TkListView' function in the TeachingDemos
package for a more interactive view.  The F stats will probably be a column in a
matrix named coefficients, just extract them from there.

Hope this helps,

--
Gregory (Greg) L. Snow Ph.D.
Statistical Data Center
Intermountain Healthcare
greg.snow at imail.org
(801) 408-8111


> -----Original Message-----
> From: r-help-bounces at r-project.org
> [mailto:r-help-bounces at r-project.org] On Behalf Of Gareth Campbell
> Sent: Monday, August 11, 2008 8:51 PM
> To: R Help
> Subject: [R] ANOVA tables - storing F values
>
> When I run a summary(anova) I get output for all of the
> elements (columns) as these are multiple - single anova
> results.  Can I store the F values?  I can't find the
> attribute of the fitted model attributes(fit) that stores
> these F values, and for that matter, P values.
>
> Thanks
>
> --
> Gareth Campbell
> PhD Candidate
> The University of Auckland
>
> P +649 815 3670
> M +6421 256 3511
> E gareth.campbell at esr.cri.nz
> gcam032 at gmail.com
>
>         [[alternative HTML version deleted]]
>
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