What package is 'grand.merge' in? --- On Wed, 7/22/09, Archana Dayalu <dayalu.arch...@gmail.com> wrote:
> From: Archana Dayalu <dayalu.arch...@gmail.com> > Subject: [R] Problem with "merge" command duplicating values > To: r-help@r-project.org > Received: Wednesday, July 22, 2009, 3:44 PM > Hello, > I am attempting to merge 8 different data sets into a > "grand merge" data > set; all their variable names are common except for the the > gas measured. > However, when I did a quick stat summary comparison of > merged data with > unmerged data, it turned out that R mysteriously duplicated > thousands of > values in the merged set and I have no idea why. I've not > had this problem > with merge in the past.... any thoughts? > > To illustrate: > > given the following objects (as data frames) with 1 unique > and 10 common > variables: > h2_flasks > co2c13_flasks > co2o18_flasks > ch4_flasks > co2_flasks > co_flasks > n2o_flasks > co2c14_flasks > > #Merge objects into one data frame ("grand merge"): > >obj.list <- ls(pattern='flasks') > >grand.merge<-merge(get(obj.list[1]),get(obj.list[2]),all=TRUE) > >for (ss in 3:length(obj.list)){ > > grand.merge<-merge(grand.merge,get(obj.list[ss]),all=TRUE) > } > > #CH4 data extracted from grand merge > >length(na.omit(grand.merge$CH4)) > [1] 29027 > > #Unmerged CH4 data only (from object ch4_flasks) > > length(na.omit(ch4_flasks$CH4)) > [1] 23739 > > #So 5000+ CH4 values are mysteriously "added" to the grand > merge file. This > "duplicated value" problem occurs for all gas variables in > the grand merged > data, in varying degrees. (For example, H2 had only 2 extra > values > mysteriously added). > > Thanks very much for any input. > Archana > > [[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. > __________________________________________________________________ The new Internet Explorer® 8 - Faster, safer, easier. Optimized for Yahoo! Get it Now for ______________________________________________ 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.