[Fernando send this reply to the list, but he does not seem to be subscribed. I'm forwarding it.]
---------- Missatge transmès ---------- Subject: Auto-discard notification Date: Wednesday 30 September 2009 From: pytables-users-boun...@lists.sourceforge.net To: pytables-users-ow...@lists.sourceforge.net The attached message has been automatically discarded. ------------------------------------------------------- Hi Dav, On Tue, Sep 29, 2009 at 4:54 PM, Dav Clark <d...@alum.mit.edu> wrote: > (Fernando, please forward this to anyone that you think might care / help!) > > I suspect you're not aware of Fernando's DataArray object, which is an > implementation of named axes on a numpy array, but you can find his slides > about it here: > > https://cirl.berkeley.edu/fperez/talks/0908_scipy_data_arrays.pdf > > The best description I can find of Dimension Scales is here: > > http://www.hdfgroup.org/HDF5/doc/HL/H5DS_Spec.pdf > > (reached by two clicks from here: > http://ftp.hdfgroup.org/HDF5/Tutor/h5dimscale.html > ) > > A dimension scale is slightly more general than the ideas captured by > DataArray in that the HDF5 Dimension Scale can actually be an array itself, > containing the appropriate values for each slice (and maybe in the future a > function + offset). Also, the same dimension scale can be used to annotate > multiple arrays. > > As I understand it, a DataArray axis is equivalent to a Dimension Scale of > type (1) in the PDF above - "no scale." I think it would be a win to extend > the DataArray concept and get that into numpy, with a clean interface to > PyTables. I haven't had time to digest all that yet, but Dimension Scales in full sound a lot, from your description above, like what Per Sederberg added in his library when we had the discussion that led to DataArray in the nipy list: http://mail.scipy.org/pipermail/nipy-devel/2009-July/001738.html While I think such functionality can be fantastic and critically necessary for many things, it also has significantly more overhead (conceptually and computationally) than the much simpler datarray idea. So I decided to go for datarray first, to see how well it would work in practice. By the way, would you (Dav) want to have a discussion on these topics at one of the upcoming py4science meetings? We could go over the ideas, you could pitch in with the hdf5 side, and we could get feedback from others to finish up the datarray prototype, which is right now lingering untouched in my github repo... Cheers, f -- Francesc Alted ------------------------------------------------------------------------------ Come build with us! The BlackBerry® Developer Conference in SF, CA is the only developer event you need to attend this year. Jumpstart your developing skills, take BlackBerry mobile applications to market and stay ahead of the curve. Join us from November 9-12, 2009. Register now! http://p.sf.net/sfu/devconf _______________________________________________ Pytables-users mailing list Pytables-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/pytables-users
