This is a great solution! Love the conciseness of your solution. And easy to understand.
Thanks again. Dan -----Original Message----- From: arun [mailto:smartpink...@yahoo.com] Sent: Monday, November 11, 2013 6:31 PM To: Lopez, Dan Subject: Re: [R] Update a variable in a dataframe based on variables in another dataframe of a different size Hi, You could use: H_DF[match(with(T_DF,paste(FY,ID,sep="_")), with(H_DF,paste(FY,ID,sep="_"))),3]<- "TER" A.K. On Monday, November 11, 2013 8:51 PM, "Lopez, Dan" <lopez...@llnl.gov> wrote: Below is how I am currently doing this. Is there a more efficient way to do this? The scenario is that I have two dataframes of different sizes. I need to update one binary factor variable in one of those dataframes by matching on two variables. If there is no match keep as is otherwise update. Also the variable being update, TT in this case should remain a binary factor variable (levels='HC','TER') HTDF2<-merge(H_DF,T_DF,by=c("FY","ID"),all.x=T) HTDF2$TT<-factor(ifelse(is.na(HTDF2$TT.y),HTDF2$TT.x,HTDF2$TT.y),labels=c("HC","TER")) HTDF2<-HTDF2[,-(3:4)] # REPRODUCIBLE EXAMPLE DATA FOR ABOVE.. > dput(H_DF) structure(list(FY = structure(c(1L, 2L, 3L, 4L, 1L, 2L, 3L, 4L, 5L), .Label = c("FY09", "FY10", "FY11", "FY12", "FY13"), class = "factor"), ID = c(1, 1, 1, 1, 2, 2, 2, 2, 2), TT = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L), .Label = c("HC", "TER"), class = "factor")), .Names = c("FY", "ID", "TT"), class = "data.frame", row.names = c(1L, 2L, 3L, 4L, 6L, 7L, 9L, 10L, 11L)) > dput(T_DF) structure(list(FY = structure(c(4L, 2L, 5L), .Label = c("FY09", "FY10", "FY11", "FY12", "FY13"), class = "factor"), ID = c(1, 2, 2), TT = structure(c(2L, 2L, 2L), .Label = c("HC", "TER"), class = "factor")), .Names = c("FY", "ID", "TT"), row.names = c(5L, 8L, 12L), class = "data.frame") Dan Lopez LLNL, HRIM - Workforce Analytics & Metrics [[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. ______________________________________________ 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.
