[R] Debugging a program written in the R language
andy_liaw at merck.com
Wed Mar 8 22:25:02 CET 2006
Firstly, some corrections:
- It's best to write code as functions in R, just like most sensible
languages. You can then debug the functions.
- (X)Emacs has versions for Windows. Prof. John Fox has kindly made
available some instructions on how Xemacs/ESS can be set up on Windows.
Now, Roger Peng has kindly made available a note on debugging R code:
Also, for compiled code linked to R, Duncan Murdoch's notes will be helpful:
Finally, there's a `debug' package on CRAN with a R News article describing
From: Thomas L Jones
> >From Tom:
> The subject is debugging a program written in the R language,under
> Windows. (Sorry, but I do not know either the Apple OS or *nix.) A
> computer program will usually not work on the first try, if only
> because of the risk of typos. Instead, it must be debugged. Roughly,
> here is the sequence:
> (1) One codes a program using the R language, and stores it on the
> hard drive, using some particular editor.
> (2) The program is fed to the R software, together with test data,
> (3) A test computation is run and bugs are spotted.
> (4) The program is corrected, using an editor, and the
> revised version
> is stored on the hard drive.
> (5) The sequence goes back to step (2) and is repeated until the
> program hopefully works.
> Unfortunately, the documentation doesn't really explain how to do all
> of this, or if it is explained in the documentation, I can't find it.
> Reading between the lines a bit, I infer that you are supposed to be
> able to use something called a History file, then sort of work
> backward in the code and make corrections. I never got it to work for
> me. Also, it is unclear how you would handle code entered six
> weeks or
> six months ago.
> That is the bad news; the good news is that some kind soul told me
> about a key trick; prepare the program in Windows text format (.txt)
> and copy it and paste it into the console. The program will now run
> from a user-defined "wrapper" or "driver" function.
> I am aware that there is an editor called Emacs which you can use if
> you are a member of the *nix community, which I am not.
> Question: How are you -supposed- to debug a program which you have
> written in the R language?
> Thomas L. Jones, Ph.D., Computer Science
> R-help at stat.math.ethz.ch mailing list
> PLEASE do read the posting guide!
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