showMethods("plot", printTo=FALSE) fails if printTo set to FALSE

-----Original Message-----
From: Prof Brian Ripley [mailto:ripley at stats.ox.ac.uk] 
Sent: 20 August 2008 13:29
To: Sklyar, Oleg (London)
Cc: r-devel at stat.math.ethz.ch
Subject: Re: [Rd] showMethods("plot", printTo=FALSE) fails if 
printTo set to FALSE

On Wed, 20 Aug 2008, Sklyar, Oleg (London) wrote:

Hi everybody,

any idea why showMethods fails with the following error 

when printTo is

set to false, i.e. to return the output as a character 

vector. It works

fine if printTo is left default as seen below. The behaviour is
consistent for any method I tried. stdin() generally works 

fine on this

system, at least when checked with: x = readLines().

Thanks,
Oleg

x = showMethods("plot", printTo=FALSE)

Error in cat(file = printTo, sep = "", ...) :
 cannot switch output to stdin

This has coerced FALSE to 0, which is connection stdin().  You cannot 
write to stdin.

I see no sign that printTo = FALSE has been implemented.  You 
could use a 
text connection, e.g.

con <- textConnection(NULL, open="w")
x <- showMethods("plot", printTo=con)
textConnectionValue(con)
close(con)

Enter a frame number, or 0 to exit

1: showMethods("plot", printTo = FALSE)
2: .showMethodsTable(fdef, includeDefs, inherited, classes 

= classes,

showEmpt
3: doFun(f, p)
4: cf("Function: ", func, " (package ", pkg, ")\n")
5: cat(file = printTo, sep = "", ...)

Selection: 0

x = showMethods("plot")

Function: plot (package graphics)
x="ANY", y="ANY"
x="SimResults", y="SimResults"
x="SimResults", y="missing"
x="TimeDateBase", y="character"
x="TimeDateBase", y="data.frameOrMatrix"
x="TimeDateBase", y="missing"
x="TimeSeries", y="missing"

sessionInfo()

R version 2.8.0 Under development (unstable) (2008-08-05 r46234)
x86_64-unknown-linux-gnu

locale:
C

attached base packages:
[1] datasets  splines   utils     stats     graphics  

grDevices methods

[8] base

other attached packages:

## 64bit RHEL 5


Dr Oleg Sklyar
Technology Group
Man Investments Ltd
+44 (0)20 7144 3803
osklyar at maninvestments.com

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-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
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Oxford OX1 3TG, UK                Fax:  +44 1865 272595