2010/10/2 Robert Kern <robert.k...@gmail.com> > On Fri, Oct 1, 2010 at 02:13, Francesc Alted <fal...@pytables.org> wrote: > > A Thursday 30 September 2010 18:20:16 Robert Kern escrigué: > >> On Wed, Sep 29, 2010 at 03:17, Francesc Alted <fal...@pytables.org> > > wrote: > >> > Hi, > >> > > >> > I'm going to give a seminar about serialization, and I'd like to > >> > describe the .npy format. I noticed that there is a variant of it > >> > called .npz that can pack several arrays in one single file. > >> > > >> > However, .npz does not use compression at all and I'm wondering > >> > what's the reason. I suppose that this is because you don't want > >> > to loose the possibility to memmap saved arrays, but can someone > >> > confirm this? > >> > >> While I suspect it's possible, I'm certain we don't have any code > >> that actually does it. Most likely the author assumed that it would > >> be faster (or tested it to be faster with their CPU/hard disk > >> configuration) to not compress. > > > > Thanks, that's good to know. And yes, I'd say that compressing with zip > > (zlib) would reduce performance for doing I/O, but most probably > > decompressing from disk media would represent an improvement in terms of > > time. At any rate, adding compression capability to .npy should be just > > one parameter away, so perhaps is a good idea adding it. > > Also some design, documentation, format version bump, and (not least) > code away. ;-) >
Oh, indeed :-) -- Francesc Alted
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