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 Kevin J Emerson
> Sent: Thursday, December 13, 2007 1:21 PM
> To: r-help at r-project.org
> Subject: [R] multiple ANOVAs
>
> Hello R help-ers,
>
>
> I have a basic question, but I have been playing with it for
> a while and haven't quite gotten a hang of how to get it
> working. I want to perform multiple one-way ANOVAs on
> subsets of data and am not sure how to do it in an automated
> way. I am thinking of doing something similar to 'aggregate'
> but I would like to collect all of the ANOVA results in a way
> in which I can get to the information from each of the
> independent ANOVAs. In effect, I would like a data frame
> with each of the subset identifiers, F and P values in the
> rows. Or a list of all of the ANOVA summaries or something like that.
>
>
>
> I would like to do an anova of the form aov(var ~ day) for
> each subset of data corresponding to "temp" and "line". I
> have lots of temps and lines and would like to do this in an
> automated fashion. I know of the aggregate function for
> doing this kind of thing to compute means etc, but I am not
> sure how to call an anova in this way. I have looked at "by"
> and "apply"
> and have tried various things but am unable to get it to work.
>
>
>
> Any help would be greatly appreciated. A sample of the
> dataset is below.
>
>
>
> Thank you for your time,
>
> Kevin
>
>
>
>
>
> temp line day var
>
> 12 WMG 1 LD 70.59
>
> 12 WMG 1 LD 100.00
>
> 12 WMG 1 LD 100.00
>
> 12 WMG 1 SD 85.00
>
> 12 WMG 1 SD 75.00
>
> 12 WMG 1 SD 90.00
>
> 12 WMG 2 LD 100.00
>
> 12 WMG 2 LD 83.33
>
> 12 WMG 2 LD 100.00
>
> 12 WMG 2 SD 91.67
>
> 14 WMG 1 LD 76.03
>
> .
>
>
>
>
>
>
>
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list
> 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.
>