Hi Duncan: Thank you very much! I checked out unique(), it does exactly what I want. But I'm still curious about if R provides "STL"(standard template library).
Best, Feng ----- Original Message ----- From: "Duncan Murdoch" <[EMAIL PROTECTED]> To: "Feng Qiu" <[EMAIL PROTECTED]> Cc: <r-help@stat.math.ethz.ch> Sent: Monday, January 01, 2007 12:36 PM Subject: Re: [R] Any container in R? > On 1/1/2007 11:22 AM, Feng Qiu wrote: >> Hi Duncan: >> Thanks for your hints. >> I'm trying to collect distinct elements in one column in a >> matrix. If there is a map, I can easily build up such a collection. While >> if using list, I have to check by myself if this element already exists >> in the collection every time I examine a new entry in the column. > > You might want to use the unique() function, or duplicated(), rather than > doing this yourself. > > Duncan Murdoch > >> >> Best, >> >> Feng >> >> ----- Original Message ----- >> From: "Duncan Murdoch" <[EMAIL PROTECTED]> >> To: "Feng Qiu" <[EMAIL PROTECTED]> >> Cc: <r-help@stat.math.ethz.ch> >> Sent: Monday, January 01, 2007 10:37 AM >> Subject: Re: [R] Any container in R? >> >> >>> On 1/1/2007 10:17 AM, Feng Qiu wrote: >>>> R has list and array to contain elements. But does R have more powerful >>>> container, such as "map" as in C++ STL? or is there such a package? >>> In what way are maps more powerful than lists? You can use names to >>> index lists. >>> >>> The other container in R is the environment; they have fairly strange >>> semantics, though. >>> >>> Duncan Murdoch >>> >>> > > > ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.