unique deletes names - intended?
Thank you for your clarification.
At 11:04 05.07.2006 +0100, Prof Brian Ripley wrote:
On Tue, 4 Jul 2006, Heinz Tuechler wrote:
Dear All, as shown in the example, unique() deletes names of vector elements. Is this intended?
Yes. Think of the vector as a set: it is supposed to immaterial which of
the duplicated elements is retained.
The help page says
An object of the same type of 'x'. but if an element is equal to
one with a smaller index, it is removed.
so it is starting with a new object, not 'x'. However, the array method
works differently, so the documentation needs clarification.
Of course, one can use indexing by !duplicated() instead.
Be careful, as you might get a method for [ and that might not do want you intended (e.g. for a time series).
Greetings, Heinz ## unique deletes names v1 <- c(a=1, b=2, c=3, e=2, a=4) unique(v1) # names deleted v1[!duplicated(v1)] # names preserved platform i386-pc-mingw32 arch i386 os mingw32 system i386, mingw32 status Patched major 2 minor 3.1 year 2006 month 07 day 01 svn rev 38471 language R version.string Version 2.3.1 Patched (2006-07-01 r38471)
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