From: Henrique Dallazuanna <wwwhsd_at_gmail.com>

Date: Sat, 05 Jun 2010 15:17:31 -0300

Date: Sat, 05 Jun 2010 15:17:31 -0300

On Sat, Jun 5, 2010 at 3:12 PM, steven mosher <moshersteven_at_gmail.com>wrote:

> Given a matrix of m*n, I want to reorder it as a vector, using a row major

*> transpose.
**>
**> so:
**>
**> > m<-matrix(seq(1,48),nrow=6,byrow=T)
**> > m
**> [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8]
**> [1,] 1 2 3 4 5 6 7 8
**> [2,] 9 10 11 12 13 14 15 16
**> [3,] 17 18 19 20 21 22 23 24
**> [4,] 25 26 27 28 29 30 31 32
**> [5,] 33 34 35 36 37 38 39 40
**> [6,] 41 42 43 44 45 46 47 48
**>
**> I want to reorder this as a vector copying by row, so that the final vector
**> has elements ordered thusly: row 1, column 1:N (m[1,1:n]) maps to
**> row 1-n, and m[2,1:n] maps to row[n+1:2n] ...
**>
**> this obviously is not a solution: as the inherent column major storage
**> paradigm of a matrix
**> defeats the approach.
**> > dim(m)<-c(48,1)
**> > m
**> [,1]
**> [1,] 1
**> [2,] 9
**> [3,] 17
**> [4,] 25
**> [5,] 33
**> [6,] 41
**> [7,] 2
**> [8,] 10
**> [9,] 18
**> [10,] 26
**> [11,] 34
**> [12,] 42
**> [13,] 3
**> [14,] 11
**> [15,] 19
**> [16,] 27
**> [17,] 35
**> [18,] 43
**> [19,] 4
**> [20,] 12
**> [21,] 20
**> [22,] 28
**> [23,] 36
**> [24,] 44
**> [25,] 5
**> [26,] 13
**> [27,] 21
**> [28,] 29
**> [29,] 37
**> [30,] 45
**> [31,] 6
**> [32,] 14
**> [33,] 22
**> [34,] 30
**> [35,] 38
**> [36,] 46
**> [37,] 7
**> [38,] 15
**> [39,] 23
**> [40,] 31
**> [41,] 39
**> [42,] 47
**> [43,] 8
**> [44,] 16
**> [45,] 24
**> [46,] 32
**> [47,] 40
**> [48,] 48
**>
**>
**> I already have a version that loops through the data ( this is actually a
**> portion of a data frame ) to reorder
**> this into a vector, but I was hoping there was an elegant way
**>
**> [[alternative HTML version deleted]]
**>
**> ______________________________________________
**> R-help_at_r-project.org 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.
**>
*

-- Henrique Dallazuanna Curitiba-Paraná-Brasil 25° 25' 40" S 49° 16' 22" O [[alternative HTML version deleted]]Received on Sat 05 Jun 2010 - 18:22:56 GMT______________________________________________ R-help_at_r-project.org 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.

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