[R] Cropping a matrix by rows

[Jeff Newmiller]

I assiduously avoid automatically generating distinct objects, and recommend that you also do so.
You have the data, and can refer to individual rows by index as you need them.
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Sent from my phone. Please excuse my brevity.

Hans Thompson <hans.thompson1 at gmail.com> wrote:

>Hello r-help,
>
>I've been banging my head against the computer in an attempt to learn
>how
>to divide my matrix into segments by rows. I want to be able to return
>each
>segment as a newly named object.  I've tried looking at the apply
>functions
>and creating a for loop but brain no work.  Here's the basic starting
>objects that I believe would be needed to separate the matrix.
>
>mat <- matrix(c(1:40),10,4)
>rowcropping <- sort(sample(2:9,2))
>rowcropping <- c(1,rowcropping,length(mat[,1]))
>mat[rowcropping[1]:rowcropping[2],]
>
>I want something like the last line as the first object but getting
>them
>all by automation  as separate objects is my goal.  Thanks.
>
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>
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