[R] merge some columns

[David Winsemius]

On Sep 2, 2011, at 9:30 AM, David Winsemius wrote:

>
> On Sep 2, 2011, at 8:34 AM, Joao Fadista wrote:
>
>> Dear all,
>>
>> I would like to know how to merge columns like:
>>
>> Input file:
>> V1 V2 V3 V4 V5 V6
>> 1  G  A  G  G  G  G
>> 2  A  A  G  A  A  G
>>
>
> Looked like an mapply-type problem:
>
> > with(dat,
>      mapply(paste,
>               list(V1, V3, V5),
>               list(V2, V4, V6),
>               MoreArgs=list(sep="/") )
>       )

There is a further refinement that is possible that will result in  
naming of the columns made possible by the behavior of the USE.NAMES  
feature of mapply. From the help page: "use names if the first ...  
argument has names, or if it is a character vector, use that character  
vector as the names";

with(dat, mapply(paste,
                    list(V1 =V1, V2=V3, V3=V5),
                     list(V2, V4, V6),
                       MoreArgs=list(sep="/") ) )
      V1    V2    V3
[1,] "G/A" "G/G" "G/G"
[2,] "A/A" "G/A" "A/G"

>
>     [,1]  [,2]  [,3]
> [1,] "G/A" "G/G" "G/G"
> [2,] "A/A" "G/A" "A/G"
>
>
>> Desired output file:
>>   V1  V2   V3
>> 1  G/A G/G G/G
>> 2  A/A G/A A/G
>>
>> So for every 2 consecutive columns merge their content into one.
>> Thanks in advance.
>>
>>
>> 	[[alternative HTML version deleted]]
> -- 
>
> David Winsemius, MD
> West Hartford, CT
>
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David Winsemius, MD
West Hartford, CT