[R] Parsing of the comment character when sourcing a file

Duncan Murdoch murdoch.duncan at gmail.com
Wed Nov 28 13:23:23 CET 2012


On 12-11-28 6:12 AM, Jim Lemon wrote:
> In the course of producing some plots for a publication, I wanted to
> mark the places where double counting of cases had occurred. I used
> three symbols, “*”, “^” and “#”. While these worked fine if the code was
> pasted into the R console, the “#” (comment character) was recognized
> even when quoted if the code was read with “source”, causing a silent
> error. Trying to escape the character didn’t work. This is mainly to
> alert those who try to use a comment character as a marker that it will
> work when the code is pasted, but not when the same code is sourced.
>

It will work in both cases.  I suspect you have some other error in your 
code.

There are differences between source() and cut-and-paste, but this isn't 
one of them.  (The main difference I can think of is that source() will 
parse the whole file and will not run if there are
syntax errors, whereas cut-and-paste will execute things one at a time.)

Duncan Murdoch




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