Re: [R] naming rows/columns in 'array of matrices'
In your example, P is a three dimensional array. You can assign names to the three dimensions using the dimnames() function. For example, this command assigns names to the first two dimensions, but leaves the third dimension without names. dimnames(P) - list(c(live, dead), c(live, dead), NULL) Jean On Fri, Jan 30, 2015 at 1:07 PM, Evan Cooch evan.co...@gmail.com wrote: Suppose I have the following situation: I have an array of 2 matrices, where each matrix is (2x2): P - array(0, c(2,2,2)) P[,,1] - matrix(c(1,2,3,4),2,2,byrow=T); P[,,2] - matrix(c(5,6,7,8),2,2,byrow=T); I want to label rows and columns of each matrix in the array, such that P would look like live dead live 12 dead 34 , , 2 live dead live 56 dead 78 I've tried 'direct, brute force approaches like rownames(P[,,1]) - c(live,dead) colnames(P[,,1]) - c(live,dead) (repeated for the second matrix), but this doesn't work. Since all of the matrices are of the same dimension(s), and since I want the same rownames and colnames for each matrix, I'm hoping there is some simply magical permutation of lapply (I'm guessing) which will do the trick. I'd also be interested in why the 'direct, brute force' approach (above) doesn't work, and what does, since I might need to manipulate row/col names for individual matrices in the array (if, say, dimensions of the matrices were not the same over the array). Thanks in advance! __ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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. [[alternative HTML version deleted]] __ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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] naming rows/columns in 'array of matrices'
I'd also be interested in why the 'direct, brute force' approach
(above) doesn't work,
Your example was a 3-dimensional array, so
rownames(P) - colnames(P) - c(live', 'dead')
would have worked; rownames() and colnames() work on dimnames[1] and
dimnames[2].
But
rownames(P[,,1])
could not have worked, because you were not assigning to the names of P; you
were assigning to something (P[,,1]) extracted from P. In effect, you were
doing the equivalent of
{P1 - P[,,1]
rownames(P1) - c('live', 'dead')
rm(P1)}
... since I might need to manipulate
row/col names for individual matrices in the array (if, say,
dimensions of the matrices were not the same over the array).
If the dimension are different you will not have an array; you'd have to have a
list of matrices.
You could then use lapply for the one constant dimension size; for example,
lp - list(P22 = matrix(ncol=2, nrow=2), P32= matrix(ncol=2, nrow=3))
lapply(lp, function(x, cn=c('live', 'dead')) {colnames(x)-cn; x})
Other than that, you'd either have to do some careful conditional coding or
apply names manually.
S
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Re: [R] naming rows/columns in 'array of matrices' | solved
On 30 Jan 2015, at 20:34 , Evan Cooch evan.co...@gmail.com wrote: The (obvious, after the fact) solution at the bottom. D'oh... [snip] Forgot I was dealing with a multi-dimensional array, not a list. So, following works fine. I'm sure there are better approaches (where 'better' is either 'cooler', or 'more flexible'), but for the moment...) P - array(0, c(2,2,2),dimnames=list(c(live,dead),c(old,young),NULL)) P[,,1] - matrix(c(1,2,3,4),2,2,byrow=T); P[,,2] - matrix(c(5,6,7,8),2,2,byrow=T); print(P); Just for completeness, this also works: P - array(0, c(2,2,2)) P[,,1] - matrix(c(1,2,3,4),2,2,byrow=T); P[,,2] - matrix(c(5,6,7,8),2,2,byrow=T); dimnames(P)[[1]] - c(live,dead) dimnames(P)[[2]] - c(live,dead) -- Peter Dalgaard, Professor, Center for Statistics, Copenhagen Business School Solbjerg Plads 3, 2000 Frederiksberg, Denmark Phone: (+45)38153501 Email: pd@cbs.dk Priv: pda...@gmail.com __ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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] naming rows/columns in 'array of matrices' | solved
You can also add names to the dimensions: dimnames(P)[[1]] - c(live,dead) dimnames(P)[[2]] - c(old,young) names(dimnames(P)) - c(status, age, NULL) P , , 1 age status old young live 1 2 dead 3 4 , , 2 age status old young live 5 6 dead 7 8 David L. Carlson Department of Anthropology Texas AM University -Original Message- From: R-help [mailto:r-help-boun...@r-project.org] On Behalf Of peter dalgaard Sent: Saturday, January 31, 2015 2:19 AM To: Evan Cooch Cc: r-help@r-project.org Subject: Re: [R] naming rows/columns in 'array of matrices' | solved On 30 Jan 2015, at 20:34 , Evan Cooch evan.co...@gmail.com wrote: The (obvious, after the fact) solution at the bottom. D'oh... [snip] Forgot I was dealing with a multi-dimensional array, not a list. So, following works fine. I'm sure there are better approaches (where 'better' is either 'cooler', or 'more flexible'), but for the moment...) P - array(0, c(2,2,2),dimnames=list(c(live,dead),c(old,young),NULL)) P[,,1] - matrix(c(1,2,3,4),2,2,byrow=T); P[,,2] - matrix(c(5,6,7,8),2,2,byrow=T); print(P); Just for completeness, this also works: P - array(0, c(2,2,2)) P[,,1] - matrix(c(1,2,3,4),2,2,byrow=T); P[,,2] - matrix(c(5,6,7,8),2,2,byrow=T); dimnames(P)[[1]] - c(live,dead) dimnames(P)[[2]] - c(live,dead) -- Peter Dalgaard, Professor, Center for Statistics, Copenhagen Business School Solbjerg Plads 3, 2000 Frederiksberg, Denmark Phone: (+45)38153501 Email: pd@cbs.dk Priv: pda...@gmail.com __ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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] naming rows/columns in 'array of matrices' | solved
The (obvious, after the fact) solution at the bottom. D'oh... On 1/30/2015 2:07 PM, Evan Cooch wrote: Suppose I have the following situation: I have an array of 2 matrices, where each matrix is (2x2): P - array(0, c(2,2,2)) P[,,1] - matrix(c(1,2,3,4),2,2,byrow=T); P[,,2] - matrix(c(5,6,7,8),2,2,byrow=T); I want to label rows and columns of each matrix in the array, such that P would look like live dead live 12 dead 34 , , 2 live dead live 56 dead 78 I've tried 'direct, brute force approaches like rownames(P[,,1]) - c(live,dead) colnames(P[,,1]) - c(live,dead) (repeated for the second matrix), but this doesn't work. Since all of the matrices are of the same dimension(s), and since I want the same rownames and colnames for each matrix, I'm hoping there is some simply magical permutation of lapply (I'm guessing) which will do the trick. Forgot I was dealing with a multi-dimensional array, not a list. So, following works fine. I'm sure there are better approaches (where 'better' is either 'cooler', or 'more flexible'), but for the moment...) P - array(0, c(2,2,2),dimnames=list(c(live,dead),c(old,young),NULL)) P[,,1] - matrix(c(1,2,3,4),2,2,byrow=T); P[,,2] - matrix(c(5,6,7,8),2,2,byrow=T); print(P); __ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.
