Re: [R] Finding code for R functions
If you're really interested in reading the source for functions and aren't interested in tracking down various methods (possibly hidden in namespaces) at the R prompt, I think it's much easier to download the R source code from CRAN and go through the original source files. -roger Wolfrum, Ed wrote: 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 -- Roger D. Peng http://www.biostat.jhsph.edu/~rpeng/ __ 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] 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
Re: [R] Finding code for R functions
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: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] 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
Re: [R] Finding code for R functions
Wolfrum, Ed wrote: 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 That is the source for prcomp. It's a one-liner, that says to call the prcomp method for whatever type of x you're passing in. As Bert said, you need to read up on methods. prcomp.default Error: object prcomp.default not found Notice that prcomp lives in namespace:stats? That's the first place to look for prcomp methods. Besides getAnywhere which Bert suggested, you can try stats:::prcomp.default to see the method. (Methods aren't necessarily in the same namespace as the generic, but that's the most common place for them.) Duncan Murdoch 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
