Re: [R] data encapsulation with classes
On Sun, 8 Apr 2007, hadley wickham wrote: On 4/8/07, Roger Bivand [EMAIL PROTECTED] wrote: 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 this? No, it isn't. You seem to be trying to deduce new-style classes from a representation used before R 2.4, (actually, still used) 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: http://www.stat.auckland.ac.nz/S-Workshop/Gentleman/Methods.pdf Unfortunately, all of those references are at least 4 years out of date when it comes to S4 methods. Is there any comprehensive reference of the current implementation of the S4 OO system apart from the source code? Not that I know of, and it is a moving target. (E.g. I asked recently about some anomalies in the S4 bit introduced for 2.4.0 and what the intended semantics are.) I've said before that I believe we can only help solve some of the efficiency issues with S4 if we have a technical manual. It is unfair to pick out S4 here, but the 'R Internals' manual is an attempt to document important implementation details (mainly by studying the code), and that has only got most of the way through src/main/*.c. -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UKFax: +44 1865 272595 __ 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.
Re: [R] data encapsulation with classes
BDR == Prof Brian Ripley [EMAIL PROTECTED]
on Mon, 9 Apr 2007 08:24:32 +0100 (BST) writes:
BDR On Sun, 8 Apr 2007, hadley wickham wrote:
On 4/8/07, Roger Bivand [EMAIL PROTECTED] wrote:
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 this?
No, it isn't. You seem to be trying to deduce new-style
classes from a representation used before R 2.4,
BDR (actually, still used)
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:
http://www.stat.auckland.ac.nz/S-Workshop/Gentleman/Methods.pdf
Unfortunately, all of those references are at least 4
years out of date when it comes to S4 methods. Is there
any comprehensive reference of the current implementation
of the S4 OO system apart from the source code?
?Methods {i.e. help(Methods)} is not about the *implementation*
but still explains quite a bit about the method dispatch part of
S4. It has had a URL to for the How S4 Methods Work technical
report by John Chambers; I've now also added a link to that from
http://developer.R-project.org/ (will only be active in ~ a day).
Martin
BDR Not that I know of, and it is a moving target. (E.g. I
BDR asked recently about some anomalies in the S4 bit
BDR introduced for 2.4.0 and what the intended semantics
BDR are.) I've said before that I believe we can only help
BDR solve some of the efficiency issues with S4 if we have
BDR a technical manual.
BDR It is unfair to pick out S4 here, but the 'R Internals'
BDR manual is an attempt to document important
BDR implementation details (mainly by studying the code),
BDR and that has only got most of the way through
BDR src/main/*.c.
BDR -- Brian D. Ripley, [EMAIL PROTECTED] Professor of
BDR Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
BDR University of Oxford, Tel: +44 1865 272861 (self) 1
BDR South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG,
BDR UK Fax: +44 1865 272595
__
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.
[R] data encapsulation with classes
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 this? Second, having attached member data with attr is there anything wrong with accessing it by the asperand (@), i.e. t = attr(t, 'test') - 4 [EMAIL PROTECTED] [1] 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@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.
Re: [R] data encapsulation with classes
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 this? 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: http://www.stat.auckland.ac.nz/S-Workshop/Gentleman/Methods.pdf Second, having attached member data with attr is there anything wrong with accessing it by the asperand (@), i.e. t = attr(t, 'test') - 4 [EMAIL PROTECTED] [1] 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@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. -- Roger Bivand Economic Geography Section, Department of Economics, Norwegian School of Economics and Business Administration, Helleveien 30, N-5045 Bergen, Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43 e-mail: [EMAIL PROTECTED] __ 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.
Re: [R] data encapsulation with classes
On 4/8/07, Roger Bivand [EMAIL PROTECTED] wrote: 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 this? 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: http://www.stat.auckland.ac.nz/S-Workshop/Gentleman/Methods.pdf Unfortunately, all of those references are at least 4 years out of date when it comes to S4 methods. Is there any comprehensive reference of the current implementation of the S4 OO system apart from the source code? Hadley __ 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.
