[R] Problem Replicating Venables & Riply Split-Plot Example

ripley@stats.ox.ac.uk ripley at stats.ox.ac.uk
Sun Feb 23 08:46:03 CET 2003


I don't know how you got oats.aov (or where you got a name similar to mine
from).

Package MASS comes with scripts for the 1999 and 2002 editions which do
what you ask.  I really don't know why you expect code written for 1993
S-PLUS to work unchanged in 2003 R (or 2003 S-PLUS), and suggest you
invest in the current edition.

On Sat, 22 Feb 2003, rab wrote:

> I'm using R 1.6.1 under Redhat Linux 8.0. I'm following the example from 
> V&R (1994) pp. 177-181. I get the split-plot ANOVA table:
> 
>  > summary(oats.aov)
> 
> Error: B
>           Df  Sum Sq Mean Sq F value Pr(>F)
> Residuals  5 15875.3  3175.1
> 
> Error: B:V
>           Df Sum Sq Mean Sq F value Pr(>F)
> V          2 1786.4   893.2  1.4853 0.2724
> Residuals 10 6013.3   601.3
> 
> Error: Within
>           Df  Sum Sq Mean Sq F value    Pr(>F)
> Nf         3 20020.5  6673.5 37.6856 2.458e-12 ***
> Nf:V       6   321.7    53.6  0.3028    0.9322
> Residuals 45  7968.7   177.1
> ---
> Signif. codes:  0 `***' 0.001 `**' 0.01 `*' 0.05 `.' 0.1 ` ' 1
> 
> 
> I need to get hold of the residuals and fitted values. The usual way of 
> using "resid" and "fitted" doesn't work I guess because this is a 
> multistratum model. The "studres" function shows up if I load the MASS 
> library. But I cannot get the "proj" and "update" functions to work as 
> they do in S-Plus:
> 
>  > oats.fm <- update(oats.aov,qr=TRUE)
> Error in update.default(oats.aov, qr = TRUE) :
>         need an object with call component
> 
> How can I get the residuals and fitted values? Wouldn't there be three 
> sets of residuals? One for the blocks (6 residuals), one for the 
> varieties (18 resduals), and another for the subplots (72 residuals)? If 
> we only looked at the varieties and blocks, this would be a randomized 
> block design using the average for each plot as the observations. There 
> would be 18 residuals. The F-statistic and p-value match the split-plot 
> ANOVA results for variety.
> 
> Thanks.
> 
> Rick B.
> 
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> 

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595




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