[R] remove component from list or data frame

[Duncan Murdoch]

On 2/8/2007 1:09 PM, Duncan Murdoch wrote:
> On 2/8/2007 12:30 PM, Jason Horn wrote:
>> Sorry to ask such a simple question, but I can't find the answer after 
>> extensive searching the docs and the web.
>> 
>> How do you remove a component from a list?  For example say you have:
>> 
>> lst<-c(5,6,7,8,9)
> 
> In R jargon, that's a vector, not a list.
>> 
>> How do you remove, for example, the third component in the list?
> 
> lst[-3] will do it.
> 
>> 
>> lst[[3]]]<-NULL     generates an error:  "Error: more elements supplied 
>> than there are to replace"
> 
> The [[ index ]] syntax only works on true lists.

Sigh.  This is just my wishful thinking.  It works on numeric vectors 
too, sometimes.  Just not here.

Duncan Murdoch

>> 
>> 
>> 
>> Also, how do you remove a row from a data frame?  For example, say you 
>> have:
>> 
>> lst1<-c(1,2,3,4,5)
>> lst2<-c(6,7,8,9,10)
>> frame<-data.frame(lst1,lst2)
>> 
>> How do you remove, for example, the second row of frame?
> 
> Same idea:
> 
> frame <- frame[-2, ]
> 
> Duncan Murdoch
>> 
>> Thanks,
>> 
>> - Jason
>> 
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> 
> ______________________________________________
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> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.