Message-ID: <alpine.LFD.1.10.0809012214470.26172@gannet.stats.ox.ac.uk>
Date: 2008-09-01T21:17:10Z
From: Brian Ripley
Subject: Question about type conversion in read.table with columns that contain "+" and "-" in R > 2.7
In-Reply-To: <48BC4F77.1010606@dkfz-heidelberg.de>
On Mon, 1 Sep 2008, Tim Beissbarth wrote:
> Somewhere in between the R-Versions 2.6 and 2.7 the behaviour of the function
> type.convert and therefore also read.table, read.csv, etc. has changed (see
> below):
>
> In 2.6 and before:
>> type.convert(c("+", "-", "+"))
> [1] + - +
> Levels: + -
>
> In 2.7 and later:
No, 2.7.0 only.
>> type.convert(c("+", "-", "+"))
> [1] 0 0 0
>
> Apparently, the character strings "+" and "-" are now interpreted as numeric
> and not any more as factors or character strings.
>
> I have quite a number of files with columns that contain "+" or "-" and would
> like to convert these to characters or factors, without having to specify the
> individual column types manually.
>
> Is there any way to still do so in a new version of R?
Even an old version of R (2.7.1)!
Please do note what the posting guide says about updating *before*
posting, and using proper version numbers (there is no 'R 2.7')
> Many thanks and best wishes,
> Tim
>
> ______________________________________________
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> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
--
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