[R] warning in summary(aov())

[R. Michael Weylandt]

On Sat, Oct 6, 2012 at 9:12 AM, Jhope <jeanwaijang at gmail.com> wrote:
> Hi R-listers,
>
> I am receiving an error - see below. Aeventexhumed is the event in which
> nesting occured, so it is defined by A, B, C. I thought as a factor was ok,
> tried to change it to as.character but it still gave me the same error. Is
> there something I should do about this error or just ignore it?
>
> Please advise, Jean
>
>>summary(aov(EDI ~ HTLIndex + Aeventexhumed + HTLIndex:Aeventexhumed,
> data=data.to.analyze))
>
>                        Df  Sum Sq Mean Sq F value Pr(>F)
> HTLIndex                6   2.435 0.40575  0.2027 0.9752
> Aeventexhumed           2   4.652 2.32601  1.1619 0.3172
> HTLIndex:Aeventexhumed 11   7.941 0.72192  0.3606 0.9680
> Residuals              98 196.193 2.00197
> 5 observations deleted due to missingness
> Warning message:
> In model.matrix.default(mt, mf, contrasts) :
>   variable 'Aeventexhumed' converted to a factor

I think you should have only seen this when Aeventexhumed was a
character -- it's nothing to worry about, just letting you know a
factor conversion had to happen (which is almost surely what you
wanted).

If you see this when Aeventexhumed is a factor already, that's
somewhat surprising. What does str(data.to.analyze) show you?

Michael

>
>
>
> --
> View this message in context: http://r.789695.n4.nabble.com/warning-in-summary-aov-tp4645253.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> 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.