[R] grep() exclude certain patterns?

Gavin Simpson gavin.simpson at ucl.ac.uk
Sat Dec 5 01:12:15 CET 2009


On Fri, 2009-12-04 at 15:18 -0600, Peng Yu wrote:
> On Fri, Dec 4, 2009 at 3:06 PM, Peng Yu <pengyu.ut at gmail.com> wrote:
> > On Fri, Dec 4, 2009 at 2:35 PM, Greg Snow <Greg.Snow at imail.org> wrote:
> >> The invert argument seems a likely candidate, you could also do perl=TRUE and use negations within the pattern (but that is probably overkill for your original question).
</snip />
> Here is another bad example. See ?rep. The Usage section has 'rep(x,
> ...)'. However, '...' is only explained later in Arguments. I know
> that it is probably because '...' is from functions underlying rep().
> But it does not matter to end users whether they are from an
> underlying function or not. Why not put the arguments in the Usage
> section?

Because '...' is the argument to rep. Should we document very argument
for every rep method in existence within this help file? The '...' has
nothing to do with functions underlying rep if you mean "inside" rep, it
is just the means by which arguments are passed from the generic to
methods for objects of particular classes.

> Similar cases can be found in the help of many functions.

Probably because that's how the S3 method system works.

If you learn how and why the R system works, things will make much more
sense.

G

<snip />
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