[R] Nested design with aov
Marcelo Martinez Palao
marmp at fcu.um.es
Sat Mar 4 13:19:46 CET 2000
Hello,
I want to do this model:
Y_ml=Mu+M+L(M)+Error
M is a fixed factor with two levels, 1 and 2
L is a random factor and nested in M, with 9 levels (9 places inside
each level of M)
amarc is the dependent variable (animal abundance)
datos is the matrix
I used the next orders in R, but there is a problem with the Df
calculation:
> m
[1] 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2
2
2 2 2
[39] 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2
> l
[1] 1 1 1 2 2 2 3 3 3 4 4 4 5 5 5 6 6 6 7 7 7 8
8
8 9
[26] 9 9 10 10 10 11 11 11 12 12 12 13 13 13 14 14 14 15 15 15 16 16
16
17 17
[51] 17 18 18 18
> amarc
[1] 4 9 1 2 1 2 9 6 15 8 10 8 10 7 3 2 1 1 2 1 1 1
4
3 2
[26] 0 2 4 0 1 0 0 0 1 1 0 4 4 4 3 0 1 0 1 0 1 0
1
0 0
[51] 3 1 0 1
> summary(aov(amarc~m+l%in%m,datos))
Df Sum Sq Mean Sq F value
Pr(>F)
m 1 130.67 130.67
15.6088 0.0002401 ***
m:l 1 19.65 19.65
2.3478 0.1316381
Residuals 51 426.94 8.37
---
Signif. codes: 0 `***' 0.001 `**' 0.01 `*' 0.05 `.' 0.1 ` ' 1
I think that the correct calculation of Df is: (Underwood, 1997.
Experiments in Ecology: their logical design and interpretation using
analysis of variance. Cambridge University Press.)
Df
m 1
m:l 16
Residuals 36
Where is the problem?
Why Df are differents?
How can I do this model?
Thaks for all.
Marcelo.
-------------- next part --------------
An embedded message was scrubbed...
From: Jan Krupa <krupa at alpha.sggw.waw.pl>
Subject: [R] archive of the mailing list?
Date: Mon, 8 Nov 1999 16:51:53 +0100 (EET)
Size: 1697
Url: https://stat.ethz.ch/pipermail/r-help/attachments/20000304/c8d0d4c9/attachment.mht
More information about the R-help
mailing list