[R] create a function with "subset" statement

[Jim Lemon]

Hi Kathryn,
If you construct a list of your logical conditions, you can pass that
to a function that evaluates them one by one and returns a list of the
resulting subsets.

subsets<-list(B="(A[,1] %in% c(1,2) & A[,2] %in% c(1,2)) | (A[,1] %in%
c(3) & A[,2] %in% c(1)) | (A[,1] %in% c(4) & A[,2] %in% c(1:4))",
 C="(A[,1] %in% c(1:4) & A[,2] %in% c(1,2))",
 D="(A[,1] %in% c(1,2) & A[,2] %in% c(1:3)) | (A[,1] %in% c(3) & A[,2]
%in% c(1,2))")

multi_subset<-function(x,sublist) {
 result_list<-list()
 for(sub in 1:length(sublist))
  result_list[[sub]]<-do.call(subset,list(x,subset=eval(parse(text=sublist[[sub]]))))
 names(result_list)<-names(sublist)
 return(result_list)
}

Jim


On Thu, Jan 29, 2015 at 7:43 AM, Karim Mezhoud <kmezhoud at gmail.com> wrote:
> Hi,
> You did the harder, it remains the easier
>
> listMatrices <- vector("list", 3)
>
> doAll <- function(A){
> B <- subset(A, (A[,1] %in% c(1,2) & A[,2] %in% c(1,2)) |
>                       (A[,1] %in% c(3)    & A[,2] %in% c(1)  )  |
>                       (A[,1] %in% c(4)    & A[,2] %in% c(1:4)) )
>
> C <- subset(A, (A[,1] %in% c(1:4) & A[,2] %in% c(1,2)) )
>
> D <- subset(A, (A[,1] %in% c(1,2) & A[,2] %in% c(1:3)) |
>                       (A[,1] %in% c(3)    & A[,2] %in% c(1,2)) )
>
> return(B)
> }
>
> B<- doAll(A)
>
>
> verify if you can:
>
>  return(c(B,C,D)).
>
> listMatrices <- doAll(A)
>
> Karim
>
>   Ô__
>  c/ /'_;~~~~kmezhoud
> (*) \(*)   ⴽⴰⵔⵉⵎ  ⵎⴻⵣⵀⵓⴷ
> http://bioinformatics.tn/
>
>
>
> On Wed, Jan 28, 2015 at 8:54 PM, Kathryn Lord <kathryn.lord2000 at gmail.com>
> wrote:
>
>> Dear R experts,
>>
>> Suppose I have a matrix A below.
>>
>> a <- rep(1:4, each=5)
>> b <- rep(1:5, 4)
>> c <- rnorm(20)
>>
>> A <- cbind(a,b,c)
>>
>> > A
>>       a b            c
>>  [1,] 1 1  0.761806718
>>  [2,] 1 2  0.239734573
>>  [3,] 1 3 -0.728339238
>>  [4,] 1 4 -0.121946174
>>  [5,] 1 5 -0.131909077
>>  [6,] 2 1 -0.069790098
>>  [7,] 2 2  1.082671767
>>  [8,] 2 3 -0.869537195
>>  [9,] 2 4 -0.417222758
>> [10,] 2 5 -2.432273481
>> [11,] 3 1  0.425432121
>> [12,] 3 2 -2.453299938
>> [13,] 3 3  0.612125174
>> [14,] 3 4 -0.005387462
>> [15,] 3 5  1.911146222
>> [16,] 4 1  0.161408685
>> [17,] 4 2  0.567118882
>> [18,] 4 3 -0.948882839
>> [19,] 4 4  0.485002340
>> [20,] 4 5 -0.551981333
>>
>>
>> With this matrix A, I'd like to create several sub-matrices, for example
>>
>>
>> B <- subset(A, (A[,1] %in% c(1,2) & A[,2] %in% c(1,2)) |
>>                       (A[,1] %in% c(3)    & A[,2] %in% c(1)  )  |
>>                       (A[,1] %in% c(4)    & A[,2] %in% c(1:4)) )
>>
>> > B
>>       a b          c
>>  [1,] 1 1  0.7618067
>>  [2,] 1 2  0.2397346
>>  [3,] 2 1 -0.0697901
>>  [4,] 2 2  1.0826718
>>  [5,] 3 1  0.4254321
>>  [6,] 4 1  0.1614087
>>  [7,] 4 2  0.5671189
>>  [8,] 4 3 -0.9488828
>>  [9,] 4 4  0.4850023
>>
>>
>> or
>>
>> C <- subset(A, (A[,1] %in% c(1:4) & A[,2] %in% c(1,2)) )
>>
>> > C
>>      a b          c
>> [1,] 1 1  0.7618067
>> [2,] 1 2  0.2397346
>> [3,] 2 1 -0.0697901
>> [4,] 2 2  1.0826718
>> [5,] 3 1  0.4254321
>> [6,] 3 2 -2.4532999
>> [7,] 4 1  0.1614087
>> [8,] 4 2  0.5671189
>>
>>
>> or
>>
>> D <- subset(A, (A[,1] %in% c(1,2) & A[,2] %in% c(1:3)) |
>>                       (A[,1] %in% c(3)    & A[,2] %in% c(1,2)) )
>>
>> > D
>>      a b          c
>> [1,] 1 1  0.7618067
>> [2,] 1 2  0.2397346
>> [3,] 1 3 -0.7283392
>> [4,] 2 1 -0.0697901
>> [5,] 2 2  1.0826718
>> [6,] 2 3 -0.8695372
>> [7,] 3 1  0.4254321
>> [8,] 3 2 -2.4532999
>>
>> and so forth.
>>
>> I am wondering if I could create matrices B, C, D etc AT ONE TIME. In order
>> to do that, I guess I need to make a "function". unfortunately, I have no
>> idea how to do that.
>>
>> Any suggestion will be greatly appreciated.
>>
>> Kathryn Lord
>>
>>         [[alternative HTML version deleted]]
>>
>> ______________________________________________
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>> http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>>
>
>         [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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.