2008/6/25 Sean Davis <[EMAIL PROTECTED]>: > First, Laurent, I am giving rpy2 a try and REALLY like what I see so > far. It is very much more intuitive, both from the point-of-view of > an R programmer as well as for python programmers. > > Data frames are very nice R data structures, so I would like to > capitalize on them and the changes included in rpy2 as much as > possible. So, how can I access the members of y (the data.frame)? If > one uses list subsetting, the values are actually reversed. I figured > out that y.getNames() will return the names of z, which I can then use > to determine the list position. Is there a way to do this with the > column names directly? > > In [34]: z = ro.r['data.frame'](x=ro.r.c(1,2,3,4),y=ro.r.c(5,6,7,8)) > > In [35]: z > Out[35]: > structure(list(y = 5:8, x = 1:4), .Names = c("y", "x"), row.names = c(NA, > -4L), class = "data.frame") > > In [36]: z[0] > Out[36]: 5:8 > > In [37]: z[0][1] > Out[37]: 6 > > In [38]: z.getNames() > Out[38]: c("y", "x") >
z.subset('y') returns a list, because data.frames are R lists, and R lists are recursive structures. z.subset('y')[0] should make it. The method "subset" mimics R's "[". There is probably the need for a counterpart to R's "[[". There will also be a proper class for data.frame (but that will be in July). L. > Thanks, > Sean > > ------------------------------------------------------------------------- > Check out the new SourceForge.net Marketplace. > It's the best place to buy or sell services for > just about anything Open Source. > http://sourceforge.net/services/buy/index.php > _______________________________________________ > rpy-list mailing list > rpy-list@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/rpy-list > ------------------------------------------------------------------------- Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://sourceforge.net/services/buy/index.php _______________________________________________ rpy-list mailing list rpy-list@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/rpy-list