[R] change in read.spss, package foreign?

[Thomas Lumley]

On Fri, 9 Sep 2005, Heinz Tuechler wrote:
> Dear Martin,
> Thank you for your answer. As I said, I appreciate this change. The
> documentation does not explain precisely, how variables with labels are
> treated now. It only tells "If SPSS value labels are converted to factors
> the underlying numerical codes will not in general be the same as the SPSS
> numerical values, since the numerical codes in R are always 1,2,3,...".
> Will now the created factor levels in any case be ordered according to the
> order of the original numerical codes in SPSS?

We don't know. We think so, based on a reasonable amount of 
experimentation, but the file format isn't documented.  We do know that 
the numerical codes R uses will always be 1,2,3,... so that there is no 
hope for having the same codes as SPSS unless the SPSS codes were also 
1,2,3...

> In general I wonder, how I could get to know such critical changes before I
> update a package instead of finding it out by chance. Is there a place,
> where a responsible R-user should look, when updating the program?

Many packages have a NEWS or ChangeLog file describing changes.  You would 
typically have to look at the source package to find them, since by Unix 
tradition they are usually in the top-level directory and so are not 
included in the binary build.

The foreign package is on svn.r-project.org, so you can see its Changelog 
there. There have been suggestions to extract these files and put them in 
the CRAN listing, but one obstacle is the lack of standardisation.

 	-thomas