[R] nested if else statements

David Winsemius dwinsemius at comcast.net
Sun Feb 5 23:38:38 CET 2012


On Feb 5, 2012, at 5:30 PM, Philip Robinson wrote:

> I have a vector of 2,1,0 I want to change to 0,1,2 respectively (the  
> data
> is allele dosages)
>
> I have tried multiple nested if/else statements and looked at the ? 
> if help
> and cannot work out what is wrong, other people have posted code  
> which is
> identical and they state works.
>
> Any help would be greatly appreciated.
>
>> A[1:20]
> [1] 1 1 0 0 1 0 1 0 1 0 0 0 1 1 0 1 1 1 0 0
>
>> B <- rep(NA,length(A))
>
>> for (i in 1:length(A)){ if(A[i]==2){B[i] <- 0} else
> +                         if(A[i]==0){B[i] <- 2} else
> +                         if(A[i]==1){B[i] <- 1}}
>
> Error in if (A[i] == 2) { : missing value where TRUE/FALSE needed

I realized after I sent my earlier message that there is no there- 
there at ?if. You should instead look at ?Control or perhaps ?"if"

-- 
David Winsemius, MD
West Hartford, CT



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