[R] data encapsulation with classes
Roger.Bivand at nhh.no
Sun Apr 8 15:08:18 CEST 2007
On Sun, 8 Apr 2007, Peter Williams wrote:
> Hi All,
> I'm new to R from a C and Octave/Matlab background. I am trying to
> construct some classes in R to which I want to attach pieces of data.
> First, is attr(obj, 'member name') <- data the accepted way of doing
No, it isn't. You seem to be trying to deduce new-style classes from a
representation used before R 2.4, but in any case it would not be
sensible. Please consult John M. Chambers. Programming with Data.
Springer, New York, 1998, and/or William N. Venables and Brian D. Ripley.
S Programming. Springer, New York, 2000, or for a shorter online resource:
> Second, having attached member data with attr is there anything wrong
> with accessing it by the asperand (@), i.e.
> > t = ""
> > attr(t, 'test') <- 4
> > t at test
>  4
> I can't find any documentation on using the asperand to access
> attributes like this. I saw it in a piece of code as I was googling
> around trying to find some information on attaching data to a class
> in R. Is this deprecated? Is this poor form? If anyone has some
> suggestions please let me know.
> Thank you
> R-help at stat.math.ethz.ch mailing list
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
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e-mail: Roger.Bivand at nhh.no
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