From: Berton Gunter <gunter.berton_at_gene.com>

Date: Wed 19 Oct 2005 - 07:38:38 EST

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 Received on Wed Oct 19 07:42:52 2005

Date: Wed 19 Oct 2005 - 07:38:38 EST

See chapter 5 on object oriented programming in the R language definition
manual. Also the ?UseMethod man page. These will explain R's (S3) method
dispatch procedures.

Finally, search on CRAN for the R New newsletter article on namespaces, which is where you'll find info on why you can't "see" certain functions. See ?getAnywhere to learn how to see code for functions in namespaces.

- Bert Gunter Genentech Non-Clinical Statistics South San Francisco, CA

"The business of the statistician is to catalyze the scientific learning process." - George E. P. Box

> -----Original Message-----

*> From: r-help-bounces@stat.math.ethz.ch
**> [mailto:r-help-bounces@stat.math.ethz.ch] On Behalf Of Wolfrum, Ed
**> Sent: Tuesday, October 18, 2005 2:27 PM
**> To: r-help@stat.math.ethz.ch
**> Subject: [R] Finding code for R functions
**>
**> Greetings,
**>
**> I am trying to figure out how to find the source code for R
**> functions. I
**> am specifically interested in finding the code for the "prcomp"
**> function. I know that typing the function name without
**> parenthesis will
**> lead to the code (or to a .Internal or .FORTRAN or .C call).
**> However, I
**> don't really understand what is going on. For example, typing "mean"
**> gives a "UseMethod" response, while typing "mean.default" give the
**> actual code:
**>
**> > mean
**> function (x, ...)
**> UseMethod("mean")
**> <environment: namespace:base>
**>
**> > mean.default
**> function (x, trim = 0, na.rm = FALSE, ...)
**> ---SNIP---
**> }
**> <environment: namespace:base>
**>
**> Why is this? What does "mean.default" mean? I tried the same
**> thing with
**> "prcomp". With the stats package loaded, I cannot get to the
**> source code
**> for "prcomp".
**>
**> > require(stats)
**> [1] TRUE
**> > prcomp
**> function (x, ...)
**> UseMethod("prcomp")
**> <environment: namespace:stats>
**> > prcomp.default
**> Error: object "prcomp.default" not found
**>
**> How do I find the prcomp code? Are there general rules for finding the
**> source code for functions that I should know?
**>
**> Thanks in Advance,
**>
**> Edward J. Wolfrum, Ph.D.
**> National Renewable Energy Laboratory
**> Golden, Colorado
**>
**> ______________________________________________
**> 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
*

>

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 Received on Wed Oct 19 07:42:52 2005

*
This archive was generated by hypermail 2.1.8
: Sun 23 Oct 2005 - 19:05:01 EST
*