You could try something like this (untested).
lapply(unique(elio2$id), function(i){
sub.mu <- exp.mu[exp.mu$id==i, ]
n <- nrow(sub.mu)
D <- matrix(0, n, n)
diag(D) <- sub.mu$deriv.link
A <- mat.cov[seq_len(n), seq_len(n)]
R <- corstr[seq_len(n), seq_len(n)]
SolveD <- solve(D)
SolveA <- solve(sqrt(A))
SolveD %*% SolveA %*% solve(R) %*% SolveA %*% SolveD
})
HTH,
Thierry
----------------------------------------------------------------------------
ir. Thierry Onkelinx
Instituut voor natuur- en bosonderzoek / Research Institute for Nature and
Forest
Cel biometrie, methodologie en kwaliteitszorg / Section biometrics, methodology
and quality assurance
Gaverstraat 4
9500 Geraardsbergen
Belgium
tel. + 32 54/436 185
[EMAIL PROTECTED]
www.inbo.be
Do not put your faith in what statistics say until you have carefully
considered what they do not say. ~William W. Watt
A statistical analysis, properly conducted, is a delicate dissection of
uncertainties, a surgery of suppositions. ~M.J.Moroney
-----Oorspronkelijk bericht-----
Van: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Namens Niccolò Bassani
Verzonden: maandag 26 november 2007 16:36
Aan: [EMAIL PROTECTED]
Onderwerp: [R] Fwd: Empty list to use in a for cycle
Dear R-users,
I'm posting a problem I already asked help for some time ago, because I'm
facing that problem once again and even because now, reading that old e-mail,
and the answer recevied, I understand I've not made myself clear.
Here's the question: I need to create an empty list of a specific length to
fill it with a quite large amount of square matrices, which is 602. The
question is that these matrices are created inside a for cycle, and I do not
know how to recall all of them one by one, except by creating an empty list
before the cycle, than assigning for each value of the i index the amtrix
computed to the first element of the empty list.
The fact is that: i've trided to create an empty list with
vector("list",602)
and then putting it in a cycle, but it didn't work. This is the cycle I've
used. To prove it works (and then the cycle itself is not a problem) there's
also the output (i.e. the last square matrix computed).
for (i in unique(elio2$id)){
sub.mu <- exp.mu[exp.mu$id==i,]
D <- matrix(0,nrow( sub.mu),nrow(sub.mu))
diag(D) <- sub.mu$deriv.link
A <- mat.cov[1:nrow(D),1:nrow(D)]
R <- corstr[1:nrow(D),1:nrow(D)]
W <- solve(D)%*%solve(sqrt(A))%*%solve(R)%*%solve(sqrt(A))%*%solve(D)
}
> W
[,1] [,2] [,3] [,4]
[1,] 3.492489e+02 -7.9324883721 0.0006286788 -0.0031046240 [2,] -7.932488e+00
17.4974625191 -1.7575467817 0.0001403319 [3,] 6.286788e-04 -1.7575467817
17.3227959738 -1.7529916860 [4,] -3.104624e-03 0.0001403319 -1.7529916860
17.2279244622
>
Does anyone knows how to insert each and every matrix like the one above in a
"omnicomprehensive" list? That's because I've to use a function requiring me to
have the matrices I need inside a list.
Thanks in advance, hope it's not a too much stupid problem!
niccolò
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