> > In addition, c() has always had a double meaning of > > (a) turning an object into a simple "vector" (an object > > without "attributes"), as in > > > c(factor(c("Cat","Dog","Cat"))) > > [1] 1 2 1 > > > c(data.frame(x=1:2,y=c("Dog","Cat"))) > > $x > > [1] 1 2 > > > > $y > > [1] Dog Cat > > Levels: Cat Dog > > To my surprise that was not documented at all on the R help page, and I've > clarified it. (BTW, at least in R it does not remove names, just all > other attributes.)
It does not remove names in Splus either, just all other attributes. I see c() used in several Splus functions as a way to convert a matrix into a vector (by removing the .Dims and .Dimnames attributes). > I think working on a concat() for R would be helpful. I vaguely recalled > something like it in the Green Book, but the index does not help (but then > it is not very complete). Splus does have a concat(). I believe it is modelled after the Green Book example. It uses a helper function called concat.two(x,y) with is generic and has 2 arguments to make it easer to write methods for. concat(x,y,z) calls concat.two(concat.two(x,y),z). concat() is not used much, but it is the Summary group functions: min, max, sum, etc. ---------------------------------------------------------------------------- Bill Dunlap Insightful Corporation bill at insightful dot com 360-428-8146 "All statements in this message represent the opinions of the author and do not necessarily reflect Insightful Corporation policy or position." ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel