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apkellogg
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Joined: Wed Feb 25, 2004 10:15 am

Help with R and matrix dimension

Wed May 02, 2012 12:03 pm

Is there anyway to set a variable in R to be equal to the row/column dimension of a matrix? If so, how would I do so? Thank you for any help!
 
ptsant
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Re: Help with R and matrix dimension

Wed May 02, 2012 1:39 pm

apkellogg wrote:
Is there anyway to set a variable in R to be equal to the row/column dimension of a matrix? If so, how would I do so? Thank you for any help!


> matrix(data=c(1:8),nrow=2,ncol=4)
     [,1] [,2] [,3] [,4]
[1,]    1    3    5    7
[2,]    2    4    6    8
> dim(matrix(data=c(1:8),nrow=2,ncol=4))
[1] 2 4
> dim(matrix(data=c(1:8),nrow=2,ncol=4))[1]
[1] 2
> dim(matrix(data=c(1:8),nrow=2,ncol=4))[2]
[1] 4
>
 
apkellogg
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Re: Help with R and matrix dimension

Wed May 02, 2012 2:02 pm

Thank you, but I don't think that is doing what I was asking about. What I want to do is import a CSV file as a matrix and then set a variable equal to the row or column count from the dim function so that functions that are done downstream can be set to the variable, instead of having to go in and customize it each time I import a new file.
 
ptsant
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Posts: 90
Joined: Mon Oct 05, 2009 12:45 pm

Re: Help with R and matrix dimension

Wed May 02, 2012 2:07 pm

apkellogg wrote:
Thank you, but I don't think that is doing what I was asking about. What I want to do is import a CSV file as a matrix and then set a variable equal to the row or column count from the dim function so that functions that are done downstream can be set to the variable, instead of having to go in and customize it each time I import a new file.

> x <- dim(matrix(data=c(1:8),nrow=2,ncol=4))[2]

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