Dear R users...
I need to split this matrix(or dataframe), for example,
z <- matrix(c(13,1,1,1,1,12,0,0,0,0,8,1,0,1,1,8,0,1,0,0,
10,1,1,1,1,3,0,1,0,0,3,1,0,1,1,6,1,1,1,1),8,5,byrow = T)
> z
[,1] [,2] [,3] [,4] [,5]
[1,] 13 1 1 1 1
[2,] 12 0 0 0 0
[3,] 8 1 0 1 1
[4,] 9 0 1 0 0
[5,] 10 1 1 1 1
[6,] 3 0 1 0 0
[7,] 3 1 0 1 1
[8,] 6 1 1 1 1
(actually, z matrix is big, about 1000*15 matrix)
to 4 matrices like this way,
#- 1st matrix--------------------------------------
13 1 1 1 1
10 1 1 1 1
6 1 1 1 1
#- 2nd matrix--------------------------------------
12 0 0 0 0
#- 3rd matrix--------------------------------------
8 1 0 1 1
3 1 0 1 1
#- 4th matrix--------------------------------------
9 0 1 0 0
3 0 1 0 0
Any comments will be greatly appreciated.
Kathryn Lord
--
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http://www.nabble.com/Splitting-matrix-into-several-small-matrices-tp24689585p24689585.html
Sent from the R help mailing list archive at Nabble.com.
Here is one way to do it:> xV1 V2 V3 V4 V5 [1,] 13 1 1 1 1 [2,] 12 0 0 0 0 [3,] 8 1 0 1 1 [4,] 9 0 1 0 0 [5,] 10 1 1 1 1 [6,] 3 0 1 0 0 [7,] 3 1 0 1 1 [8,] 6 1 1 1 1> # create the row indices based on columns 2-3 > x.i <- split(seq(nrow(x)), paste(x[,2], x[,3])) > x.i$`0 0` [1] 2 $`0 1` [1] 4 6 $`1 0` [1] 3 7 $`1 1` [1] 1 5 8> # now create a list of the matrices > lapply(x.i, function(a) x[a,,drop=FALSE])$`0 0` V1 V2 V3 V4 V5 [1,] 12 0 0 0 0 $`0 1` V1 V2 V3 V4 V5 [1,] 9 0 1 0 0 [2,] 3 0 1 0 0 $`1 0` V1 V2 V3 V4 V5 [1,] 8 1 0 1 1 [2,] 3 1 0 1 1 $`1 1` V1 V2 V3 V4 V5 [1,] 13 1 1 1 1 [2,] 10 1 1 1 1 [3,] 6 1 1 1 1>On Mon, Jul 27, 2009 at 6:46 PM, kathie<kathryn.lord2000 at gmail.com> wrote:> > Dear R users... > > I need to split this matrix(or dataframe), for example, > > z <- matrix(c(13,1,1,1,1,12,0,0,0,0,8,1,0,1,1,8,0,1,0,0, > ? ? ? ? ? ? ? ? ?10,1,1,1,1,3,0,1,0,0,3,1,0,1,1,6,1,1,1,1),8,5,byrow = T) > > >> z > ? ? [,1] [,2] [,3] [,4] [,5] > [1,] ? 13 ? ?1 ? ?1 ? ?1 ? ?1 > [2,] ? 12 ? ?0 ? ?0 ? ?0 ? ?0 > [3,] ? ?8 ? ?1 ? ?0 ? ?1 ? ?1 > [4,] ? ?9 ? ?0 ? ?1 ? ?0 ? ?0 > [5,] ? 10 ? ?1 ? ?1 ? ?1 ? ?1 > [6,] ? ?3 ? ?0 ? ?1 ? ?0 ? ?0 > [7,] ? ?3 ? ?1 ? ?0 ? ?1 ? ?1 > [8,] ? ?6 ? ?1 ? ?1 ? ?1 ? ?1 > > > (actually, z matrix is big, about 1000*15 matrix) > > to 4 matrices like this way, > > > #- 1st matrix-------------------------------------- > 13 ? ?1 ? ?1 ? ?1 ? ?1 > 10 ? ?1 ? ?1 ? ?1 ? ?1 > ?6 ? ?1 ? ?1 ? ?1 ? ?1 > > #- 2nd matrix-------------------------------------- > 12 ? ?0 ? ?0 ? ?0 ? ?0 > > > #- 3rd matrix-------------------------------------- > 8 ? ?1 ? ?0 ? ?1 ? ?1 > 3 ? ?1 ? ?0 ? ?1 ? ?1 > > > #- 4th matrix-------------------------------------- > 9 ? ?0 ? ?1 ? ?0 ? ?0 > 3 ? ?0 ? ?1 ? ?0 ? ?0 > > > > Any comments will be greatly appreciated. > > Kathryn Lord > -- > View this message in context: http://www.nabble.com/Splitting-matrix-into-several-small-matrices-tp24689585p24689585.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > 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. >-- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem that you are trying to solve?
Bill.Venables at csiro.au
2009-Jul-28 06:13 UTC
[R] Splitting matrix into several small matrices
I take it you want to split the matrix into sub-matrices for which some collection of columns is constant. In your case this is the last four columns. Here's an idea:> z <- matrix(c(13,1,1,1,1,12,0,0,0,0,8,1,0,1,1,8,0,1,0,0,+ 10,1,1,1,1,3,0,1,0,0,3,1,0,1,1,6,1,1,1,1),8,5,byrow = T)> z[,1] [,2] [,3] [,4] [,5] [1,] 13 1 1 1 1 [2,] 12 0 0 0 0 [3,] 8 1 0 1 1 [4,] 8 0 1 0 0 [5,] 10 1 1 1 1 [6,] 3 0 1 0 0 [7,] 3 1 0 1 1 [8,] 6 1 1 1 1> ind <- do.call(paste, data.frame(z[, 2:5]))> split(data.frame(z), ind)$`0 0 0 0` X1 X2 X3 X4 X5 2 12 0 0 0 0 $`0 1 0 0` X1 X2 X3 X4 X5 4 8 0 1 0 0 6 3 0 1 0 0 $`1 0 1 1` X1 X2 X3 X4 X5 3 8 1 0 1 1 7 3 1 0 1 1 $`1 1 1 1` X1 X2 X3 X4 X5 1 13 1 1 1 1 5 10 1 1 1 1 8 6 1 1 1 1>Bill Venables http://www.cmis.csiro.au/bill.venables/ -----Original Message----- From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf Of kathie Sent: Tuesday, 28 July 2009 8:47 AM To: r-help at r-project.org Subject: [R] Splitting matrix into several small matrices Dear R users... I need to split this matrix(or dataframe), for example, z <- matrix(c(13,1,1,1,1,12,0,0,0,0,8,1,0,1,1,8,0,1,0,0, 10,1,1,1,1,3,0,1,0,0,3,1,0,1,1,6,1,1,1,1),8,5,byrow = T)> z[,1] [,2] [,3] [,4] [,5] [1,] 13 1 1 1 1 [2,] 12 0 0 0 0 [3,] 8 1 0 1 1 [4,] 9 0 1 0 0 [5,] 10 1 1 1 1 [6,] 3 0 1 0 0 [7,] 3 1 0 1 1 [8,] 6 1 1 1 1 (actually, z matrix is big, about 1000*15 matrix) to 4 matrices like this way, #- 1st matrix-------------------------------------- 13 1 1 1 1 10 1 1 1 1 6 1 1 1 1 #- 2nd matrix-------------------------------------- 12 0 0 0 0 #- 3rd matrix-------------------------------------- 8 1 0 1 1 3 1 0 1 1 #- 4th matrix-------------------------------------- 9 0 1 0 0 3 0 1 0 0 Any comments will be greatly appreciated. Kathryn Lord -- View this message in context: http://www.nabble.com/Splitting-matrix-into-several-small-matrices-tp24689585p24689585.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.