check for missing values.
Tal



On Wed, Sep 23, 2009 at 3:27 PM, pompon <julien.pompon@agr.gc.ca> wrote:

>
> Hi,
>
> I am performing a repeated measures 2-way ANOVA  to assess the influence of
> plant and leaf on aphid fecundity. Fecundity is measured for each aphid on
> a
> single leaf.
> Here is what I typed.
>
> wingless <- reshape(Wingless,
>                            varying =
>
> list(c("d0","d1","d2","d3","d4","d5","d6","d7","d8","d9","d10","d11","d12","d13","d14","d15","d16")),
>                            v.names = c("fecundity"), timevar = "time",
>                            direction = "long")
>
> wingless.aov <- aov(fecundity ~ factor(time) * clip.cage * plant +
> Error(factor(id)), data = wingless)
>
> summary(wingless.aov)
>
> and I obtained
>
> Error: factor(id)
>                       Df Sum Sq Mean Sq F value  Pr(>F)
> factor(time)            4 56.789  14.197  3.0613 0.05925 .
> clip.cage               1 14.149  14.149  3.0509 0.10621
> plant                   1  3.251   3.251  0.7010 0.41880
> factor(time):clip.cage  1  0.304   0.304  0.0655 0.80240
> clip.cage:plant         1 17.114  17.114  3.6903 0.07880 .
> Residuals              12 55.652   4.638
> ---
> Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
>
> Error: Within
>                              Df Sum Sq Mean Sq F value  Pr(>F)
> factor(time)                  16 340.83   21.30 11.5222 < 2e-16 ***
> factor(time):clip.cage        16  27.34    1.71  0.9242 0.54195
> factor(time):plant            16  46.36    2.90  1.5673 0.07783 .
> factor(time):clip.cage:plant  16  24.50    1.53  0.8281 0.65304
> Residuals                    255 471.44    1.85
> ---
> Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
>
> I don't understand why I have the factor(time) inmy between subject
> results,
> whereas with a similar set of data I don't.
>
> Thank you very much,
> Julien Pompon.
> --
> View this message in context:
> http://www.nabble.com/repeated-measures-tp25531110p25531110.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
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> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>



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