On 6/4/07, Stan Hopkins <[EMAIL PROTECTED]> wrote: > I'm new to R and am trying to extract the factors of a dataframe using > numeric indices (e.g. df[1]) that are input to a function definition instead > of the other types of references (e.g. df$out). df[1] is a list(?) whose > class is "dataframe". These indexed lists can be printed successfuly but are > not agreeable to the plot() and lm() functions shown below as are their > df$out references. Reading the documentation for plot and lm hasn't helped > yet. Thanks in advance - Stan.
> > df=data.frame(out=1:4*3,pred1=1:4,pred2=1:4*2) > > regression=function(tble,a,b) > + { > + plot.new() > + plot(tble[a]~tble[b]) > + lmm=lm(tble[a]~tble[b]) > + abline(lmm) > + anova(lmm) > + } > > df[1] > out > 1 3 > 2 6 > 3 9 > 4 12 but df[[1]] is the first column of df in its native form. I think of the distinction as like the difference between an element of a set, which is what the "[[" function returns, and the subset consisting of a single element, which is what the "[" function returns. ______________________________________________ R-help@stat.math.ethz.ch 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.