[R] List operations in R
jim holtman
jholtman at gmail.com
Fri Nov 30 01:18:03 CET 2007
To remove the 'names':
> x2 <- c('1001_a'='123', '1002_b'='345')
> x2
1001_a 1002_b
"123" "345"
> names(x2) <- NULL
> x2
[1] "123" "345"
>
To append:
> z <- letters[1:4]
> z
[1] "a" "b" "c" "d"
> z <- c(z,x2)
> z
[1] "a" "b" "c" "d" "123" "345"
>
On Nov 29, 2007 7:07 PM, Srinivas Iyyer <srini_iyyer_bio at yahoo.com> wrote:
> hello:
>
> I am very confused when it comes to list operations in
> R.
>
> I seek help in the following problem.
>
> I have two different vectors
>
> myIDs - a character vector with no names to their
> elements
>
> x2 - another character vector derived from unlisting a
> list where an element has both a name and value.
>
> I am not happy the way x2 is with names and values to
> every element.
>
>
> > myIDs[1:10]
> [1] "54898" "7083" "7031" "7083" "4175" "4605"
> "7494" "5111" "960" "990"
>
> >> class(myIDs)
> [1] "character"
>
>
>
>
> Similarly x2 objects is
>
> > x2[1:4]
> 1000_at 1001_at 1002_f_at 1003_s_at
> "5595" "7075" "1557" "643"
>
> > class(x2)
> [1] "character"
>
>
> I am not happy the way x2 is right now. I do not want
> names of the elements. I want to write to another
> object x3 that has only values of the elements and not
> their names.
>
> How can I do that?
>
> I can give a [[]] to get the value of element.
> > x2[[1]]
> [1] "5595"
>
> When I try to give a range of numbers:
> > x2[[1:4]]
> Error in x2[[1:4]] : attempt to select more than one
> element
>
>
> Frustrated, I wanted to create another object z, and
> append all values of x2 to z.
>
> > z = c()
> > for(i in 1:length(x2)){
> + append(z,x2[[i]],after=length(z))}
> > length(z)
> [1] 0
>
>
> now z is empty. this is really frustrating. Can
> someone help me please how to deal in this situation.
>
> Thanks
> Sri
>
>
> ____________________________________________________________________________________
> Be a better pen pal.
>
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>
--
Jim Holtman
Cincinnati, OH
+1 513 646 9390
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