Hi Simon, You almost had it! Just need to move the negation outside the rest of the logic, and remove the quotes from year. Not actually tested (no data), but I think
newdata<- subset(bpa, !(State=="Connecticut" & year<2010)) should do it. Best, Ista On Tue, Jan 25, 2011 at 1:34 PM, Simon Kiss <simonjk...@yahoo.ca> wrote: > Dear colleagues, I have a dataset that looks as below. > > I would like to make a new dataset that excludes the cases which are joint > conjunctions of particular state names and years, so Connecticut and 2010, > Maryland and 2010 and Vermont and 2010. > > I'm trying the following subset code: > newdata<- subset(bpa, (!State=="Connecticut" & year<"2010")) > > It appears that it's only evaluating both criteria independently and not > jointly, so this is returning all cases in 2008 and 2009, leaving out > connecticut for those years as well. > How do I get subset to return a dataset based on the joint occurrence of > values of two variables? > > Yours, Simon Kiss > > str(bpa) > 'data.frame': 150 obs. of 5 variables: > $ State : Factor w/ 50 levels "Alabama","Alaska",..: 1 2 3 4 5 6 7 8 9 10 > ... > $ year : num 2008 2008 2008 2008 2008 ... > $ ban : num 0 0 0 0 0 0 0 0 0 0 ... > $ partisan: Factor w/ 3 levels "democrat","mixed",..: 1 1 1 1 1 1 1 2 3 2 ... > $ news : num 1.67 2 0 0 2.38 ... > ********************************* > Simon J. Kiss, PhD > Assistant Professor, Wilfrid Laurier University > 73 George Street > Brantford, Ontario, Canada > N3T 2C9 > Cell: +1 519 761 7606 > > ______________________________________________ > 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. > -- Ista Zahn Graduate student University of Rochester Department of Clinical and Social Psychology http://yourpsyche.org ______________________________________________ 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.
