R help - Jan 2011 - How to join matrices of different row length from a list

Hi,

I have several matrix in a list, for example:
e
[[1]]
     [,1] [,2]
[1,]    1    3
[2,]    2    4

[[2]]
     [,1] [,2]
[1,]    1    4
[2,]    2    5
[3,]    3    6

[[3]]
     [,1] [,2]
[1,]    2    1

I would like to join them by column i.e.
     [,1] [,2]   [,3] [,4][,5] [,6]
[1,]    1    3   1    4    2    1
[2,]    2    4   2    5   NA  NA
[3,]   NA  NA  3    6   NA   NA

I have tried  do.call(cbind,e) but I get this error message as the rows are
of different length-
Error in function (..., deparse.level = 1)  :
  number of rows of matrices must match (see arg 2)

Can anyone advise me please?

Thanks Emma


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try this:

matLis <- list(matrix(1:4, 2, 2), matrix(1:6, 3, 2),
     matrix(2:1, 1, 2))

n <- max(sapply(matLis, nrow))
do.call(cbind, lapply(matLis, function (x)
     rbind(x, matrix(, n-nrow(x), ncol(x)))))


I hope it helps.

Best,
Dimitris


On 1/6/2011 11:56 AM, emj83 wrote:
>
> Hi,
>
> I have several matrix in a list, for example:
> e
> [[1]]
>       [,1] [,2]
> [1,]    1    3
> [2,]    2    4
>
> [[2]]
>       [,1] [,2]
> [1,]    1    4
> [2,]    2    5
> [3,]    3    6
>
> [[3]]
>       [,1] [,2]
> [1,]    2    1
>
> I would like to join them by column i.e.
>       [,1] [,2]   [,3] [,4][,5] [,6]
> [1,]    1    3   1    4    2    1
> [2,]    2    4   2    5   NA  NA
> [3,]   NA  NA  3    6   NA   NA
>
> I have tried  do.call(cbind,e) but I get this error message as the rows are
> of different length-
> Error in function (..., deparse.level = 1)  :
>    number of rows of matrices must match (see arg 2)
>
> Can anyone advise me please?
>
> Thanks Emma
>
>
-- 
Dimitris Rizopoulos
Assistant Professor
Department of Biostatistics
Erasmus University Medical Center

Address: PO Box 2040, 3000 CA Rotterdam, the Netherlands
Tel: +31/(0)10/7043478
Fax: +31/(0)10/7043014
Web: http://www.erasmusmc.nl/biostatistiek/

Excellent- that is just what I need. Thank you so much for your prompt help,

Emma
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On Thu, Jan 6, 2011 at 5:56 AM, emj83 <stp08emj at shef.ac.uk>
wrote:
>
> Hi,
>
> I have several matrix in a list, for example:
> e
> [[1]]
> ? ? [,1] [,2]
> [1,] ? ?1 ? ?3
> [2,] ? ?2 ? ?4
>
> [[2]]
> ? ? [,1] [,2]
> [1,] ? ?1 ? ?4
> [2,] ? ?2 ? ?5
> [3,] ? ?3 ? ?6
>
> [[3]]
> ? ? [,1] [,2]
> [1,] ? ?2 ? ?1
>
> I would like to join them by column i.e.
> ? ? [,1] [,2] ? [,3] [,4][,5] [,6]
> [1,] ? ?1 ? ?3 ? 1 ? ?4 ? ?2 ? ?1
> [2,] ? ?2 ? ?4 ? 2 ? ?5 ? NA ?NA
> [3,] ? NA ?NA ?3 ? ?6 ? NA ? NA
>
> I have tried ?do.call(cbind,e) but I get this error message as the rows are
> of different length-
> Error in function (..., deparse.level = 1) ?:
> ?number of rows of matrices must match (see arg 2)
>
One reasonably simple approach is to convert your matrices to time
series (either ts series or zoo series) as cbind.ts and cbind.zoo both
NA fill.

L <- list(matrix(1:4, 2, 2), matrix(1:6, 3, 2), matrix(2:1, 1, 2))


# using ts
M <- unclass(do.call(cbind, lapply(L, ts)))
tsp(M) <- colnames(M) <- NULL

# With zoo its slightly shorter:

library(zoo)
M <- coredata(do.call(cbind, lapply(L, zoo)))
colnames(M) <- NULL


We can omit the colnames(M) <- NULL part in both cases if the list
itself or the constituent matrices have column names, e.g.

L <- list(A = matrix(1:4, 2, 2), B = matrix(1:6, 3, 2), C = matrix(2:1, 1,
2))

# or

L <- list(cbind(a = 1:2, b = 3:4), cbind(c = 1:3, d = 4:6), cbind(e = 2, f =
1))

-- 
Statistics & Software Consulting
GKX Group, GKX Associates Inc.
tel: 1-877-GKX-GROUP
email: ggrothendieck at gmail.com

Dear Emma,

there is a 'cbind.na', 'rbind.na' and 'data.frame.na'
function in my qpcR
package.

library(qpcR)
matLis <- list(matrix(1:4, 2, 2), matrix(1:6, 3, 2),
     matrix(2:1, 1, 2))
do.call(cbind.na, matLis)

They are essentially the generic functions extended with an internal fill.

You might also want to try these examples:

## binding
cbind.na(1, 1:7) # the '1' (= shorter vector) is NOT recycled but filled
cbind.na(1:8, 1:7, 1:5, 1:10) # same with many vectors
rbind.na(1:8, 1:7, 1:5, 1:10) # or in rows

a <- matrix(rnorm(20), ncol = 4) # unequal size matrices
b <- matrix(rnorm(20), ncol = 5)
cbind.na(a, b) # works, in contrast to original cbind
rbind.na(a, b) # works, in contrast to original rbind

## data frame with unequal size vectors
data.frame.na(A = 1:7, B = 1:5, C = letters[1:3], 
              D = factor(c(1, 1, 2, 2))) 
              
## convert a list with unequal length list items
## to a data frame
z <- list(a = 1:5, b = letters[1:3], c = matrix(rnorm(20), ncol = 2))
do.call(data.frame.na, z)

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Can this be used in matplot(x,y,....)? where x and y have matching rows.
However, each column may have different rows or length. Thanks. Sheng

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