[R] how to get column/row info from a dist object?
Dear R users; Is it possible to get the row and column number of a particular entry in a dist object? Let's say that I want to find the position of the value 1.1837 (the last entry on the dist object below), that is [6,3]. Can I get those values without transforming the object to a matrix?, i.e. working with the dist object only. 12 3 2 0.23935864 3 0.56655914 0.71923104 4 0.15272561 0.37926989 0.43931332 5 0.17728654 0.13355685 0.73025495 6 0.61783536 0.52055379 1.18374889 Thanks for any idea PM __ 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] how to get column/row info from a dist object?
But the dist object is not structured with rows and columns. i.e. x=1:4 d=dist(x) 1 2 3 2 1 3 2 1 4 3 2 1 str(d) Class 'dist' atomic [1:6] 1 2 3 1 2 1 ..- attr(*, Size)= int 4 ..- attr(*, Diag)= logi FALSE ..- attr(*, Upper)= logi FALSE ..- attr(*, method)= chr euclidean ..- attr(*, call)= language dist(x = x) So, AFAIK if you want to get references for rows and columns you need to make it an object that indeed has rows and columns, i.e. a matrix. See ?which to obtain the reference you want in a matrix. Regards, Francisco Pedro Mardones wrote: Dear R users; Is it possible to get the row and column number of a particular entry in a dist object? Let's say that I want to find the position of the value 1.1837 (the last entry on the dist object below), that is [6,3]. Can I get those values without transforming the object to a matrix?, i.e. working with the dist object only. 12 3 2 0.23935864 3 0.56655914 0.71923104 4 0.15272561 0.37926989 0.43931332 5 0.17728654 0.13355685 0.73025495 6 0.61783536 0.52055379 1.18374889 Thanks for any idea PM __ 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] how to get column/row info from a dist object?
Thanks Francisco; I'm trying to avoid the step of converting a dist object into a matrix because I'm working with matrices of more than 5000 rows x 5000 columns. I just was wondering if someone knew any trick to do that. On 5/11/07, Francisco J. Zagmutt [EMAIL PROTECTED] wrote: But the dist object is not structured with rows and columns. i.e. x=1:4 d=dist(x) 1 2 3 2 1 3 2 1 4 3 2 1 str(d) Class 'dist' atomic [1:6] 1 2 3 1 2 1 ..- attr(*, Size)= int 4 ..- attr(*, Diag)= logi FALSE ..- attr(*, Upper)= logi FALSE ..- attr(*, method)= chr euclidean ..- attr(*, call)= language dist(x = x) So, AFAIK if you want to get references for rows and columns you need to make it an object that indeed has rows and columns, i.e. a matrix. See ?which to obtain the reference you want in a matrix. Regards, Francisco Pedro Mardones wrote: Dear R users; Is it possible to get the row and column number of a particular entry in a dist object? Let's say that I want to find the position of the value 1.1837 (the last entry on the dist object below), that is [6,3]. Can I get those values without transforming the object to a matrix?, i.e. working with the dist object only. 12 3 2 0.23935864 3 0.56655914 0.71923104 4 0.15272561 0.37926989 0.43931332 5 0.17728654 0.13355685 0.73025495 6 0.61783536 0.52055379 1.18374889 Thanks for any idea PM __ 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. __ 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] how to get column/row info from a dist object?
which(..., arr.ind=TRUE) On 5/11/07, Pedro Mardones [EMAIL PROTECTED] wrote: Dear R users; Is it possible to get the row and column number of a particular entry in a dist object? Let's say that I want to find the position of the value 1.1837 (the last entry on the dist object below), that is [6,3]. Can I get those values without transforming the object to a matrix?, i.e. working with the dist object only. 12 3 2 0.23935864 3 0.56655914 0.71923104 4 0.15272561 0.37926989 0.43931332 5 0.17728654 0.13355685 0.73025495 6 0.61783536 0.52055379 1.18374889 Thanks for any idea PM __ 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. -- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem you are trying to solve? __ 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] how to get column/row info from a dist object?
On 5/11/07, Pedro Mardones [EMAIL PROTECTED] wrote:
Dear R users;
Is it possible to get the row and column number of a particular entry
in a dist object?
Let's say that I want to find the position of the value 1.1837 (the
last entry on the dist object below), that is [6,3]. Can I get those
values without transforming the object to a matrix?, i.e. working with
the dist object only.
12 3
2 0.23935864
3 0.56655914 0.71923104
4 0.15272561 0.37926989 0.43931332
5 0.17728654 0.13355685 0.73025495
6 0.61783536 0.52055379 1.18374889
Thanks for any idea
PM
Try this.
row.col - function(dd, value) {
if (length(value) == 1) {
g - grep(value, dd)
N - attr(dd, Size)
idx - cumsum(seq(N-1, 1))
ic - sum(g idx) + 1
ir - g - c(0,idx)[ic] + ic
c(row = ir, col = ic)
} else sapply(value, row.col, dd = dd)
}
# test
set.seed(1)
x - matrix(rnorm(100), nrow=5)
dd - dist(x)
dd
dd[7]
row.col(dd, dd[7])
row.col(dd, unlist(dd))
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and provide commented, minimal, self-contained, reproducible code.
