[R] leveneTest - output

[John Fox]

Dear Hermann,

> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> project.org] On Behalf Of Hermann Norpois
> Sent: Tuesday, October 01, 2013 8:07 AM
> To: r-help
> Subject: [R] leveneTest - output
> 
> Hello,
> 
> I have a question concerning the output of leveneTest. I don't
> understand
> the "7" in my output

That's the denominator df for F.

Best,
 John

> 
> Levene's Test for Homogeneity of Variance (center = median)
>       Df F value Pr(>F)
> group  2  0.0173 0.9829
>        7        # Where does this number come from?
> 
> Thanks.
> Hermann
> 
> 
> > res
>    group.ID    qtrait
> 1         0 6462.3288
> 2         0  816.7808
> 3         0 6031.3356
> 4         0 1013.5274
> 5         0 1517.2500
> 6         1 1585.2740
> 7         1 2481.6781
> 8         1 8871.5753
> 9         2 4913.5274
> 10        2  833.7329
> > ltest <- leveneTest (qtrait~group.ID, res)
> > ltest
> Levene's Test for Homogeneity of Variance (center = median)
>       Df F value Pr(>F)
> group  2  0.0173 0.9829
>        7
> > dput (res)
> structure(list(group.ID = structure(c(1L, 1L, 1L, 1L, 1L, 2L,
> 2L, 2L, 3L, 3L), .Label = c("0", "1", "2"), class = "factor"),
>     qtrait = c(6462.32876712329, 816.780821917808, 6031.33561643836,
>     1013.52739726027, 1517.25, 1585.27397260274, 2481.67808219178,
>     8871.57534246575, 4913.52739726027, 833.732876712329)), .Names =
> c("group.ID",
> "qtrait"), row.names = c(NA, -10L), class = "data.frame")
> 
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> 
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