Have a look at match and merge. Hadley On Wednesday, September 8, 2010, Michael Haenlein <haenl...@escpeurope.eu> wrote: > Dear all, > > I'm working with two data frames. > > The first frame (agg_data) consists of two columns. agg_data[,1] is a unique > ID for each row and agg_data[,2] contains a continuous variable. > > The second data frame (geo_data) consists of several columns. One of these > columns (geo_data$ZCTA) corresponds to the unique ID in the first data > frame. The problem is that only a subset of the unique ID present in the > first data frame also appears in the second data fame. > > What I would like to do is to add another column to the second data frame > (geo_data) that includes the value of the continuous variable from the first > frame that corresponds to the unique ID. To put it differently, I want R to > look at each row in the second data frame, look for the unique ID > (geo_data$ZCTA), look for the same unique ID in the first data frame and > then paste the value from the continous variable as a new column into the > second data frame. I hope I'm somewhat clear here ... > > Is there a convenient way of doing this? > > Thanks very much in advance, > > Michael > > [[alternative HTML version deleted]] > > ______________________________________________ > r-h...@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. >
-- Assistant Professor / Dobelman Family Junior Chair Department of Statistics / Rice University http://had.co.nz/ ______________________________________________ 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.
