[R] merge 2 data frame based on more than 2 variables

[Wensui Liu]

what if the names are different in 2 data frames?


On 8/14/06, Simon Blomberg <blomsp at ozemail.com.au> wrote:
> Wensui Liu wrote:
> > Dear Lister,
> >
> > I understand merge() can be used to join 2 data frames based on 1 variable.
> > But how about merge based on more than 2 variables?
> >
> > Thank you so much!
> >
> >
> Just specify the 2 (or more) variable names in a column vector for "by")
>
> merge(dat1, dat2, by= c("VarA", "VarB"))
>
> assuming both data frames have columns VarA and VarB.
>
> --
> Simon Blomberg, B.Sc.(Hons.), Ph.D, M.App.Stat.
> Centre for Resource and Environmental Studies
> The Australian National University
> Canberra ACT 0200
> Australia
> T: +61 2 6125 7800 email: Simon.Blomberg_at_anu.edu.au
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>


-- 
WenSui Liu
(http://spaces.msn.com/statcompute/blog)
Senior Decision Support Analyst
Health Policy and Clinical Effectiveness
Cincinnati Children Hospital Medical Center