From: Gabor Grothendieck <ggrothendieck_at_myway.com>

Date: Tue 22 Mar 2005 - 10:23:24 EST

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 Received on Tue Mar 22 10:33:28 2005

Date: Tue 22 Mar 2005 - 10:23:24 EST

Bill Simpson <William.Simpson <at> drdc-rddc.gc.ca> writes:

*:
*

: I want to flatten a matrix and unflatten it again. Please tell me how to

*: do it.
**:
**: 1. given a matrix:
**: x1 y1 z1
**: x2 y2 z2
**: ...
**: xk yk zk
**: convert it to a vector:
**: x1, y1, z1, x2, y2, z2, ..., xk, yk, zk
**:
**: 2. given a vector:
**: x1, y1, z1, x2, y2, z2, ..., xk, yk, zk
**: convert it to a matrix
**: x1 y1 z1
**: x2 y2 z2
**: ...
**: xk yk zk
**:
**: It is known that the number of dimensions is 3.
**:
*

myvector <- c(t(mymatrix))

mymatrix <- matrix(myvector, byrow = TRUE, nc=3)

If column-wise is ok rather than row-wise as you show, then omit t() in the first line and byrow = TRUE in the second.

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 Received on Tue Mar 22 10:33:28 2005

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