[R] R-help with apply and ccf
Dear R gurus, I would like to use the ccf function on two matrices that are each 196000 x 12. Ideally, I want to be able to go row by row for the two matrices using apply for the ccf function and get one 196000 X 1 array output. The apply function though wants only one array, no? Basically, is there a way to use apply when there are two arrays in order to do something like correlation on a row by row basis? Thanks for your help Michael [[alternative HTML version deleted]] __ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Re: [R] R-help with apply and ccf
You could combine them with cbind, and then split the rows again inside
the function you're calling with apply.
Mat - cbind(mat1, mat2)
apply(Mat, 1, function(x){
row.mat1 - x[seq_len(length(x)/2)]
row.mat2 - x[length(x)/2 + seq_len(length(x)/2)]
cor(row.mat1, row.mat2)
})
Cheers,
Thierry
ir. Thierry Onkelinx
Instituut voor natuur- en bosonderzoek / Reseach 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 Michael Andric
Verzonden: dinsdag 22 mei 2007 17:35
Aan: r-help@stat.math.ethz.ch
Onderwerp: [R] R-help with apply and ccf
Dear R gurus,
I would like to use the ccf function on two matrices that are
each 196000 x 12. Ideally, I want to be able to go row by
row for the two matrices using apply for the ccf function and
get one 196000 X 1 array output. The apply function though
wants only one array, no? Basically, is there a way to use
apply when there are two arrays in order to do something like
correlation on a row by row basis?
Thanks for your help
Michael
[[alternative HTML version deleted]]
__
R-help@stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
__
R-help@stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
Re: [R] R-help with apply and ccf
I understand you to want correlations of corresponding rows (** not ccf, which returns a vector ccf for each pair of rows). If that is so, 1) ... in theory, diag(cor(t(A), t(B)) would work without apply, except 196,000 rows is probably too large, and it is probably too inefficient to compute and then throw away all the off-diagonals anyway. 2. ##Use a 3d array. ar - array(c(A,B),dim=c(dim(A),2)) ## this can also be done by abind() in the abind package apply(ar,1,function(x)cor(x[,1],x[,2])) ## Value is a vector 3. ## probably simplest and best sapply(seq_along(nrow(a)),function(i)cor(a[i,],b[i,])) ## Note: value is a vector, not an array Bert Gunter Genentech Nonclinical Statistics -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Michael Andric Sent: Tuesday, May 22, 2007 8:35 AM To: r-help@stat.math.ethz.ch Subject: [R] R-help with apply and ccf Dear R gurus, I would like to use the ccf function on two matrices that are each 196000 x 12. Ideally, I want to be able to go row by row for the two matrices using apply for the ccf function and get one 196000 X 1 array output. The apply function though wants only one array, no? Basically, is there a way to use apply when there are two arrays in order to do something like correlation on a row by row basis? Thanks for your help Michael [[alternative HTML version deleted]] __ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. __ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
