[R] converting apply output

[Andrew Beckerman]

Thanks eric... I figured this routine out as well.

cvt<-function(dat){
x<-as.list(rep(0,dim(dat)[2]))
for(i in 1:dim(dat)[2]){
x[[i]]<-dat[,i]
x}}

# get ragged array of 1's
dat<-apply(mat,2,function(x) which(x==1))
# deal with this using cvt to creat list
if(is.null(dim(dat))) dat2<-dat else dat2<-cvt(dat)

On 23 Jun 2004, at 13:13, Eric Lecoutre wrote:

>
> Hi,
>
> Why not try with the data.frame structure, wich internally yet  
> consists in a list:
>
> > lapply(as.data.frame(m1),function(x) which(x==1))
> $V1
> [1] 8 9
> $V2
> [1]  9 10
> [...]
>
> Eric
>
> At 12:53 23/06/2004, Andrew Beckerman wrote:
>> Hi -
>>
>> platform powerpc-apple-darwin6.8
>> status
>> major    1
>> minor    9.0
>> year     2004
>>
>> I am trying to deal with the output of apply().  As indicated, when  
>> each call to 'FUN' returns a vector of length 'n', then 'apply'
>> returns an array of dimension 'c(n, dim(X)[MARGIN])'.  However, I  
>> would like this to be a list in the same format as is produced when  
>> 'FUN' return vectors of different lengths ('apply'   returns a list  
>> of length 'dim(X)[MARGIN]').
>>
>> e.g.
>> tt1<-c(0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0,  
>> 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, ,0 ,0 ,0 ,0 ,0  
>> ,0 ,1 ,0 ,1 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,1 ,1 ,0 ,0 ,0 ,0 ,0 ,0 ,0 ,1 ,0  
>> ,0 ,0 ,1 ,0 ,0 ,0 ,0 ,0 ,1 ,0 ,0, 0, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0,  
>> 0, 0, 0, 0, 0, 0, 1, 0, 1, 0)
>> m1<-matrix(tt1,10,10)
>> out<-apply(m1,2,function(x) which(x==1))
>>
>> produces an array,
>> > out
>>      [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10]
>> [1,]    8    9    7    8    6    7    6    6    6     7
>> [2,]    9   10    8    9    8    8   10   10    7     9
>>
>> but I would like out as a list of 10 elements with two elements in  
>> each, e.g.
>>
>> [[1]]
>> [1]  8 9
>>
>> [[2]]
>> [1] 9 10
>> etc.
>>
>> I have tried apply(out,2,function(x) list(x))), but the subsrcripting  
>> is not equal to the pattern when FUN returns a vectors of different  
>> length.  Any help would be appreciated.
>>
>> Cheers
>> andrew
>>
>> ______________________________________________
>> R-help at stat.math.ethz.ch mailing list
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>> PLEASE do read the posting guide!  
>> http://www.R-project.org/posting-guide.html
>
> Eric Lecoutre
> UCL /  Institut de Statistique
> Voie du Roman Pays, 20
> 1348 Louvain-la-Neuve
> Belgium
>
> tel: (+32)(0)10473050
> lecoutre at stat.ucl.ac.be
> http://www.stat.ucl.ac.be/ISpersonnel/lecoutre
>
> If the statistics are boring, then you've got the wrong numbers.  
> -Edward Tufte
>
>
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Dr. Andrew Beckerman
Department of Animal and Plant Sciences, University of Sheffield,
Alfred Denny Building, Western Bank, Sheffield S10 2TN, UK
ph +44 (0)114 222 0026; fx +44 (0)114 222 0002
http://www.shef.ac.uk/beckslab
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