The test that a slope differs by group is a test that the variable*group interaction equals zero (overall test). Maybe searching post-hoc comparisons in regression will give you some leads.
On Tue, Sep 15, 2009 at 10:57 AM, Jun Shen <jun.shen...@gmail.com> wrote: > Hi, all, > > I am thinking to compare a group of slopes from regression lines to see if > they are different overall, and then make specific comparisons between > groups. How can I achieve that in R? I searched the archives and there are > only discussions about comparing two lines a time. Thanks. > > A sample data set is like the following. I would like to compare the > regression slopes between the five groups. Thanks for your help. > > data<-data.frame(x=rep(1:10,5),y=rnorm(50),group=rep(1:5,each=10)) > > Jun Shen > > [[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.
