From ripley at stats.ox.ac.uk  Tue Aug  5 06:48:20 2008
From: ripley at stats.ox.ac.uk (Prof Brian Ripley)
Date: Tue, 5 Aug 2008 05:48:20 +0100 (BST)
Subject: [Rd] importing explicitly declared missing values in read.spss
 (foreign)
In-Reply-To: <18809176.post@talk.nabble.com>
References: <18776776.post@talk.nabble.com>
	<alpine.LFD.1.10.0808011654200.7435@gannet.stats.ox.ac.uk>
	<18809176.post@talk.nabble.com>
Message-ID: <alpine.LFD.1.10.0808050547380.11005@gannet.stats.ox.ac.uk>

I've put up an experimental version at

http://www.stats.ox.ac.uk/pub/R/foreign_0.8-28.1.tar.gz

See the new 'use.missings' argument.  It does what I think should happen
in your example and the other one I tried, but more experience would be
helpful.

On Mon, 4 Aug 2008, Jeroen Ooms wrote:

Please don't silently excise context -- see the posting guide for the
rights of posters to be quoted fairly (and your usage of my posting fails
to be fair).

> Prof Brian Ripley wrote:
>>
>>> From the messages you get I do not believe this is a recent version of
> read.spss (message 2 no longer appears)...
>
> I am sorry you are right here, I was using an outdated version of foreign. I
> have updated my packages. My current version is now R version 2.7.1
> (2008-06-23) with foreign_0.8-28.
>
> I have experimented importing some spss datafiles, mostly from the sample
> data files that are included with SPSS. Most of these files do not generate
> any warnings, so I am not sure this is related to the missingness. However,
> the problem of read.spss() not returning any information on missingness
> persists in all of these datafiles.
>
>
> Prof Brian Ripley wrote:
>>
>> All that is 'harmfull' is that you are not told that value labels NA and
>> NAP were to be regarded as 'missing' in SPSS.  We've no idea whether if
>> would be a more or less egregious choice to map them to R's NA, and
>> certainly are not in a position to assert 'far less harmfull' in general.
>
> Of course the 'least harmfull' behavior of the function completely depends
> on the data and the user's intentions. I was explicitly suggesting making
> the mapping of missing values to <NA>'s optional, to give users who consider
> this appropriate, the option to replace these missings. I do not claim this
> to be the best default behavior, just a very useful feature.

-- 
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] importing explicitly declared missing values in read.spss (foreign)
Prof Brian Ripley