[R] detect repeated number in a vector
Dear R users, I have this vector that consists numeric numbers. Is there a command that detects the repeated numbers in a vector and returns the index of the repeated numbers (or the actual numbers)? For example, v - c(3,4,5,7,4). The command would return me index 2 and 5 (or the repeated number, 4). Thank you very much, Julia -- View this message in context: http://www.nabble.com/detect-repeated-number-in-a-vector-tp19884768p19884768.html Sent from the R help mailing list archive at Nabble.com. __ R-help@r-project.org 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.
Re: [R] detect repeated number in a vector
On 08/10/2008 2:36 PM, liujb wrote: Dear R users, I have this vector that consists numeric numbers. Is there a command that detects the repeated numbers in a vector and returns the index of the repeated numbers (or the actual numbers)? For example, v - c(3,4,5,7,4). The command would return me index 2 and 5 (or the repeated number, 4). duplicated() comes close, but the first occurence doesn't count as a duplication: duplicated(v) [1] FALSE FALSE FALSE FALSE TRUE To convert into values, you can index v by it: v[duplicated(v)] [1] 4 and to find which indices are duplicated, indices - seq_along(v) indices[duplicated(v)] [1] 5 If you really want to include the the first one, you can do something like: indices[ v %in% v[duplicated(v)] ] [1] 2 5 Duncan Murdoch __ R-help@r-project.org 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.
Re: [R] detect repeated number in a vector
Can this be an answer ? which(v %in% names(table(v)[table(v)1])) [1] 2 5 Nael On Wed, Oct 8, 2008 at 8:36 PM, liujb [EMAIL PROTECTED] wrote: Dear R users, I have this vector that consists numeric numbers. Is there a command that detects the repeated numbers in a vector and returns the index of the repeated numbers (or the actual numbers)? For example, v - c(3,4,5,7,4). The command would return me index 2 and 5 (or the repeated number, 4). Thank you very much, Julia -- View this message in context: http://www.nabble.com/detect-repeated-number-in-a-vector-tp19884768p19884768.html Sent from the R help mailing list archive at Nabble.com. __ R-help@r-project.org 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. [[alternative HTML version deleted]] __ R-help@r-project.org 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.
Re: [R] detect repeated number in a vector
Duncan, Thank you so much. It is exactly what I was looking for. However, for some reason, indices() does not work (Error: could not find function indices). I used which(), it worked. Thanks again for the help, Julia Duncan Murdoch-2 wrote: On 08/10/2008 2:36 PM, liujb wrote: Dear R users, I have this vector that consists numeric numbers. Is there a command that detects the repeated numbers in a vector and returns the index of the repeated numbers (or the actual numbers)? For example, v - c(3,4,5,7,4). The command would return me index 2 and 5 (or the repeated number, 4). duplicated() comes close, but the first occurence doesn't count as a duplication: duplicated(v) [1] FALSE FALSE FALSE FALSE TRUE To convert into values, you can index v by it: v[duplicated(v)] [1] 4 and to find which indices are duplicated, indices - seq_along(v) indices[duplicated(v)] [1] 5 If you really want to include the the first one, you can do something like: indices[ v %in% v[duplicated(v)] ] [1] 2 5 Duncan Murdoch __ R-help@r-project.org 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. -- View this message in context: http://www.nabble.com/detect-repeated-number-in-a-vector-tp19884768p19887359.html Sent from the R help mailing list archive at Nabble.com. __ R-help@r-project.org 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.
