Message-ID: <17497.43741.908109.939891@mithrandir.hornik.net>
Date: 2006-05-04T07:18:53Z
From: Kurt Hornik
Subject: abline and its documentation
In-Reply-To: <20060503220436.GA18145@phenix.sram.qc.ca>
>>>>> Fran?ois Pinard writes:
> Hi, people. The documentation of abline says:
> Usage:
> abline(a, b, untf = FALSE, ...)
> abline(h=, untf = FALSE, ...)
> abline(v=, untf = FALSE, ...)
> abline(coef=, untf = FALSE, ...)
> abline(reg=, untf = FALSE, ...)
> so suggesting that h= and v= usages are exclusive. There are examples
> in the mailing list archives of using both at the same time, and I find
> convenient, for example, doing:
> abline(h=0, v=0, ...)
> for bolding the position of the origin or the axes through the origin.
> By doing so, we are using undocumented capabilities of abline and
> consequently, writing bugged R code. It does not matter so much
> interactively, but scripts may be more sensitive.
> Would it be acceptable to amend abline documentation, so to commit the
> capability of abline to do both h= and v= at once? Or even combined
> with intercept and slope? (abline is able to do all three at once
> already!) Then, R users and code could more safely rely on this.
> Just a suggestion, and not a big matter, of course! :-)
Afaic, I would change the \usage to just given the function synopsis
(removing \synopsis along the way), and indicate the various usage
scenarios via details and/or examples.
-k