On 3/10/11 9:51 AM, Francesc Alted wrote: > A Thursday 10 March 2011 18:05:11 Christopher Barker escrigué: >> NOTE: this looks like it could use a "growable" numpy array, much >> like one I've written before -- maybe it's time to revive that >> project and use it here, fixing some performance issues while I'm at >> it. > > A growable array would be indeed very useful in many situations. My > carray project [1] is another attempt to create such an object. It > grows (or shrink) arrays by adding (removing) chunks, so they are fast > beasts for performing these operations. I suppose this is more or less > like your approach.
I don't think so -- my approach is a lot simpler that I think carray is: it acts much like a python list: 1) it pre-allocates extra space when an array is created. 2) when you append, it uses that extra space 3) when the extra space is used up, it re-allocates the entire array, with some more extra room And to keep it really simple, I'm using a numpy array internally, and np.ndarray.resize to grow it. It can only be grown on the first axis (C-order). IIUC, carray is doing a lot more smarts about keeping the array in chunks that can be individually manipulated, which is very cool.NOt to mention the compression! > I also thought about implementing ragged arrays in carray, like those > you are suggesting, but not sure when they will be ready for public > consumption. That would be very cool, and I think you are right, the facilities in carray could make a really nice ragged array. > Perhaps it is a good time to join efforts and create a nice 'growable' > array package? Sure, but I don't know that I have much to offer, except maybe some test and timing code. By the way, it would be great to have a growable array that could be efficiently used in Cython code -- so you could accumulate a bunch of native C datatype data easily. -Chris -- Christopher Barker, Ph.D. Oceanographer Emergency Response Division NOAA/NOS/OR&R (206) 526-6959 voice 7600 Sand Point Way NE (206) 526-6329 fax Seattle, WA 98115 (206) 526-6317 main reception chris.bar...@noaa.gov _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
