help text for xlim

xlim belongs to plot.window(), which is what plot.default() passes it to.
It is documented in both places.  It is not necessarily relevant to a 
general plot() (which might call lattice, for example).

I'd suggest adding an alias or concept to plot.window.Rd.  And 'asp' does 
have an alias and concept on that page.

On Tue, 29 Apr 2008, Duncan Murdoch wrote:

I think you're right, xlim is harder to discover than it should be.  If we 
added the right "concept" marker to the page, then help.search() would find 
it.  But a lot of things are mentioned on the plot.default page; how many 
others there are just as hard as xlim to find?  I'd rather not fix xlim 
today, and then something else tomorrow, etc:  I'd prefer it if someone 
looked carefully at what the concepts are on that page and whether it is the 
best place to find descriptions of them.  Any volunteers?

Duncan Murdoch

Henrik Parn wrote:

Dear R-developers,

A student asked me today of how to specify the limits of the x-axis. I knew 
that he should use xlim, but I tried to encourage him to have a try himself 
with the various help functions. I do not judge if he used the correct 
search strategy or right key words, but anyway here is what he tried: he 
looked at ?plot. There xlim is not mentioned. He checked ?par. There you 
find xlim mentioned under the xaxs argument, but not how to specify xlim 
itself. He also failed with help.search("x-axis limits") and 
help.search("x-axis range") and dito apropos(). Neither did Rsitesearch() 
for these terms leed him reasonably straight to the xlim. Finally, he 
checked under See Also: plot.default, and there xlim is mentioned as 
argument, but it does not appear in the examples.

I think it is fair enough that xlim does not appear under ?plot or ?par, 
but would it be possible to add an explicit xlim example under plot.default 
and perhaps to make xlim more likely to be hit by 'xlim-related' searches?


Best regards,

Henrik

 > sessionInfo()

R version 2.7.0 (2008-04-22)
i386-pc-mingw32

locale:
LC_COLLATE=English_United Kingdom.1252;LC_CTYPE=English_United 
Kingdom.1252;LC_MONETARY=English_United 
Kingdom.1252;LC_NUMERIC=C;LC_TIME=English_United Kingdom.1252

WinXP