Your variable loc_type combines information from two variables (loc and type). Since you are subsetting on loc, why not just plot by type?
boxplot(var1~type, data[data$loc=="nice",]) ---------------------------------------------- David L Carlson Associate Professor of Anthropology Texas A&M University College Station, TX 77843-4352 > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-bounces@r- > project.org] On Behalf Of Jim Lemon > Sent: Thursday, March 21, 2013 4:05 AM > To: carol white > Cc: r-h...@stat.math.ethz.ch > Subject: Re: [R] boxplot > > On 03/21/2013 07:40 PM, carol white wrote: > > Hi, > > It must be an easy question but how to boxplot a subset of data: > > > > data = read.table("my_data.txt", header = T) > > boxplot(data$var1[data$loc == "nice"]~data$loc_type[data$loc == > "nice"]) > > #in this case, i want to display only the boxplot loc == "nice" > > #doesn't display the boxplot of only loc == "nice". It also displays > loc == "mice" > > > Hi Carol, > It's them old factors sneakin' up on you. Try this: > > boxplot(data$var1[data$loc == "nice"]~ > as.character(data$loc_type[data$loc == "nice"])) > > Jim > > ______________________________________________ > 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.