[R] how to eliminate an element of a list

[David Winsemius]

On Aug 13, 2010, at 4:06 PM, fishkbob wrote:

>
>> list<-seq(2,10,2)
>> list
> [1]  2  4  6  8 10
>> list[-which(2==list)]
> [1]  4  6  8 10
>
> using the which() will let you remove things from a list that have a
> specified value... I usually use the
>
> blah<- blah[-which(TRUE==is.na(blah)) ]
>
> which will remove all NA values in your list

Although which() is useful when used with "[" because it avoids the NA  
indexing problem,  it is entirely superfluous here.

  blah<- blah[-is.na(blah) ]   # will be more efficient

>

-- 

David Winsemius, MD
West Hartford, CT