# [R] Merging data in arrays

Fri Feb 22 14:11:38 CET 2013

```Hello,

I bet there are simpler solutions but I'm not thinking of anything else,
right now.

fun <- function(x, y){
f <- function(a, b){
a <- as.data.frame(a)
b <- as.data.frame(b)
names(a)[1] <- names(b)[1] <- "V1"
res <- merge(b, a, by = "V1")
if(nrow(res) > 0) as.matrix(res) else NULL
}
dx <- dim(x)[3]
dy <- dim(y)[3]
res <- list()
ires <- 0
for(idx in seq_len(dx)){
for(idy in seq_len(dy)){
tmp <- f(x[, , idx], y[, , idy])
if(!is.null(tmp)){
ires <- ires + 1
res[[ires]] <- tmp
}
}
}
k <- nrow(res[[1]])
m <- ncol(res[[1]])
n <- length(res)
array(unlist(res), dim = c(k, m, n))
}

G <- fun(C, E)
identical(F, G)  #TRUE

Hope this helps,

Em 22-02-2013 03:40, Ray Cheung escreveu:
> Thanks, Jeff.
>
> Here is a simplified hypothetical sample (sorry for the clumsy code):
> A1 <- matrix(1:5, nrow=5, ncol=1)
> A2 <- matrix(6:10, nrow=5, ncol=1)
> A3 <- matrix(11:15, nrow=5, ncol=1)
> A4 <- matrix(16:20, nrow=5, ncol=1)
> A5 <- matrix(21:25, nrow=5, ncol=1)
> A6 <- matrix(26:30, nrow=5, ncol=1)
> B1 <- matrix(c(A1, A2, A3), nrow=5, ncol=3)
> B2 <- matrix(c(A2, A3, A4), nrow=5, ncol=3)
> B3 <- matrix(c(A3, A4, A5), nrow=5, ncol=3)
> C <- array(c(B1, B2, B3), dim = c(5,3,3))
> D1 <- matrix(c(A1, A4, A5), nrow=5, ncol=3)
> D2 <- matrix(c(A3, A5, A6), nrow=5, ncol=3)
> E <- array(c(D1, D2), dim = c(5,3,2))
> In the above example, I want to merge array C to array E by matching the
> column 1. That is, the resultant array F should look like this:
> F1 <- matrix(c(A1, A4, A5, A2, A3), nrow=5, ncol=5)
> F2 <- matrix(c(A3, A5, A6, A4, A5), nrow=5, ncol=5)
> F <- array(c(F1, F2), dim = c(5,5,2))
>
> I want to have a more general way to do the merging because in reality, the
> dimensions of C and E are very over thousands. Thank you very much.
>
> Best Regards,
> ray
>
>
> On Fri, Feb 22, 2013 at 11:28 AM, Jeff Newmiller
> <jdnewmil at dcn.davis.ca.us>wrote:
>
>> I think this specification is insufficient to respond accurately to.
>> Please make a reproducible subset of your data (or simulated data) and
>> provide it in dput form, and describe your desired result data set more
>> clearly.
>>
>>
>> http://stackoverflow.com/questions/5963269/how-to-make-a-great-r-reproducible-example
>>
>> ---------------------------------------------------------------------------
>> Jeff Newmiller                        The     .....       .....  Go Live...
>> DCN:<jdnewmil at dcn.davis.ca.us>        Basics: ##.#.       ##.#.  Live
>> Go...
>>                                        Live:   OO#.. Dead: OO#..  Playing
>> Research Engineer (Solar/Batteries            O.O#.       #.O#.  with
>> /Software/Embedded Controllers)               .OO#.       .OO#.  rocks...1k
>> ---------------------------------------------------------------------------
>> Sent from my phone. Please excuse my brevity.
>>
>> Ray Cheung <ray1728 at gmail.com> wrote:
>>
>>> Dear All,
>>>
>>> I've 2 arrays A and B:
>>>
>>> dim(A) = 100, 10, 1000
>>> dim(B) = 100, 20, 900
>>>
>>> I know there are 5 columns of values common to both arrays. I want to
>>> how to merge the 2 arrays. Thanks in advance!
>>>
>>> Best Regards,
>>> Ray
>>>
>>>        [[alternative HTML version deleted]]
>>>
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>>> and provide commented, minimal, self-contained, reproducible code.
>>
>>
>
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>
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