change in read.spss, package foreign?
Dear Thomas, Thanks a lot for your extensive answer. Heinz
At 08:53 09.09.2005 -0700, Thomas Lumley wrote:
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