[R] request: How to get column name

[Dimitris Rizopoulos]

try this:

x <- c(3,3,3,3,0,0,0,0,5,5,5,5,8,8,8,8)
x <- matrix(x, nrow=4)

which(colSums(x == 0) == nrow(x))

I hope it helps.

Best,
Dimitris


Muhammad Azam wrote:
> Dear R community
> I have a problem regarding which of the column in a matrix contains all of zero elements. e.g.
> x=c(3,3,3,3,0,0,0,0,5,5,5,5,8,8,8,8); x=matrix(x, nrow=4)
> the output is
>   
>> x
>>     
>      [,1] [,2] [,3] [,4]
> [1,]    3    0    5    8
> [2,]    3    0    5    8
> [3,]    3    0    5    8
> [4,]    3    0    5    8
> In this case the required column is second so the result should be "2". How can i get it? 
>
>  
> best regards
>
> Muhammad Azam 
>
>
>
>       
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-- 
Dimitris Rizopoulos
Assistant Professor
Department of Biostatistics
Erasmus University Medical Center

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