Actually you got it, the data sets you created are a perfect example (row#1 and row#2 in DF1 have the same V1 and differ only in V2) , but here is the problem: row#2 in DF1 exists in DF1 and not in DF2, however it does not show in the Difference. It seems to me that both V1 and V2 should be considered when calculating the difference.
----- Original Message ---- From: Jorge Ivan Velez <[EMAIL PROTECTED]> To: joseph <[EMAIL PROTECTED]> Sent: Sunday, September 14, 2008 11:14:11 AM Subject: Re: [R] difference of two data frames Hi Joseph, I'm not sure if I understood your point, but try this: # Data sets DF1= data.frame(V1=c(1,1,2,3,3,4,5,5,6), V2= letters[1:9]) DF2= data.frame(V1=1:3, V2= letters[1:3]) # Difference DF1[! DF1$V1 %in% DF2$V1,] HTH, Jorge On Sun, Sep 14, 2008 at 1:57 PM, joseph <[EMAIL PROTECTED]> wrote: Hi Jorge both commands work; can you extend it to several coulmns? the reason I am asking is that in my real data the uniqueness of the rows is made of all the columns; in other words V1 might have duplicates. Thanks ----- Original Message ---- From: Jorge Ivan Velez <[EMAIL PROTECTED]> To: joseph <[EMAIL PROTECTED]> Cc: r-help@r-project.org Sent: Sunday, September 14, 2008 10:23:33 AM Subject: Re: [R] difference of two data frames Hi Joseph, Try this: DF1[!DF1$V1%in%DF2$V1,] subset(DF1,!V1%in%DF2$V1) HTH, Jorge On Sun, Sep 14, 2008 at 12:49 PM, joseph <[EMAIL PROTECTED]> wrote: Hello I have 2 data frames DF1 and DF2 where DF2 is a subset of DF1: DF1= data.frame(V1=1:6, V2= letters[1:6]) DF2= data.frame(V1=1:3, V2= letters[1:3]) How do I create a new data frame of the difference between DF1 and DF2 newDF=data.frame(V1=4:6, V2= letters[4:6]) In my real data, the rows are not in order as in the example I provided. Thanks much Joseph [[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. [[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.