[R] ANOVA precision

[Bill Venables]

> Rers,
> 
> Hi, I just ran a one-way ANOVA using R and compared the output to a
> one-way ANOVA I created using SAS on the same data set.
> 
> Here are the results:
> 
> R
> 
>            DF  Sum Sq   Mean Sq  F value  Pr(>F)
> Base       3   27.7449  9.2483   107.99   < 2.2e-16 *** 
> Residuals 32    2.7449  0.0856
> 
> SAS
> 
>             Sum Of
> Source DF   Squares Mean   Square       F Value   Pr > F
> Model   3   27.69085439    9.23028480   107.55    <.0001
> Error  32    2.74643538    0.08582611
> 
> In a "philosophical" sense, are the rounding differences worth worrying
> about (they may not be significant in this case, but sometimes the
> differences are in the second digit), or is this an example of "use at
> your own risk"?

Well, if SAS has an accuracy problem I'm sure they would be glad to
hear of it and keen to fix it up...  :-)

-- 
Bill Venables,      Statistician,     CMIS Environmetrics Project
CSIRO Marine Labs, PO Box 120, Cleveland, Qld,  AUSTRALIA.   4163
Tel: +61 7 3826 7251           Email: Bill.Venables at cmis.csiro.au    
Fax: +61 7 3826 7304      http://www.cmis.csiro.au/bill.venables/



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