From ripley at stats.ox.ac.uk  Wed Aug 20 14:28:48 2008
From: ripley at stats.ox.ac.uk (Prof Brian Ripley)
Date: Wed, 20 Aug 2008 13:28:48 +0100 (BST)
Subject: [Rd] showMethods("plot",
 printTo=FALSE) fails if printTo set to FALSE
In-Reply-To: <1A68FCB28DE72F4BA3B967E6506CCE43030496AA@mildnpexmb01.maninvestments.ad.man.com>
References: <1A68FCB28DE72F4BA3B967E6506CCE43030496AA@mildnpexmb01.maninvestments.ad.man.com>
Message-ID: <alpine.LFD.1.10.0808201325350.17839@gannet.stats.ox.ac.uk>

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
>
>
> **********************************************************************
> The contents of this email are for the named addressee(s...{{dropped:22}}
>
> ______________________________________________
> R-devel at r-project.org mailing list
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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)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595



[Rd] showMethods("plot", printTo=FALSE) fails if printTo set to FALSE
Prof Brian Ripley