> -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of [EMAIL PROTECTED] > Sent: Tuesday, February 21, 2006 12:54 PM > To: [email protected] > Subject: [R] How to select only certain rows when making a new > dataframe? > > > Dear R-users, > > I have two data frames. The "FIRST" data frame has 100 rows, the > "SECOND" data frame has only 50 rows. > > The data frames have different variables in columns ("VAR1," "VAR2," > etc) but they share a column called "ID" that contains a unique > identifer linking the two data frames. > > I would like to make a "THIRD" data frame containing just the rows of > the "FIRST" data frame that match the rows (on "ID") in the "SECOND" > data frame. > > >THIRD=data.frame(FIRST$ID,FIRST$VAR1,FIRST$VAR2) > > How can I modify this line to include in "THIRD" just the rows in > "FIRST" that match the rows in "SECOND"? (i.e., contain the same value > in the shared "ID" column).
List this? one <- data.frame(ID = 1:100, Var1 = runif(100), Var2 = runif(100)) two <- data.frame(ID = 26:50, VarA = runif(50), VarB = runif(50)) three <- one[one$ID == two$ID,] ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
