R help - Aug 2011 - Help: Sort components of a vector with indices tracked in R

Dear All,
I would like to know how to sort a vector of numeric values such that we know
the original index of each ordered component. Say, we have
c <- c(1,4,3,2)
csort <- sort(c,descreasing=FALSE)
With a few components of c, we can manually find out:
 csort[1] = 1 = c[1], ie, the original index of csort[1] is 1, 
csort[2] =2 =c[4], ie, the original index of csort[2] is 4.

When length(c) is very large, manual checking is infeasible. 
We can set up a for loop to compare and extract the index. However, is there an
easier way to do this, so that the output is the sorted vector and their
corresponding original indices.
Thanks
Chee
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If you make your vector a data.frame, you will have row numbers accompanying
your sorting

df<-data.frame(V1=c(1,4,3,2))
df$rows<-row.names(df)

df[order(df$V1),]

also, you shouldn't use c as a variable name since its an important R
function...

see your example :)

Justin


On Tue, Aug 23, 2011 at 4:59 PM, Chee Chen <chee.chen@yahoo.com> wrote:
> Dear All,
> I would like to know how to sort a vector of numeric values such that we
> know the original index of each ordered component. Say, we have
> c <- c(1,4,3,2)
> csort <- sort(c,descreasing=FALSE)
> With a few components of c, we can manually find out:
>  csort[1] = 1 = c[1], ie, the original index of csort[1] is 1,
> csort[2] =2 =c[4], ie, the original index of csort[2] is 4.
>
> When length(c) is very large, manual checking is infeasible.
> We can set up a for loop to compare and extract the index. However, is
> there an easier way to do this, so that the output is the sorted vector and
> their corresponding original indices.
> Thanks
> Chee
>        [[alternative HTML version deleted]]
>
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