My use case is a biliterl filter: It is a convolution-like filter used mainly in image-processing, which may use relatively large convolution kernels (in the order of 50x50). I would like to run the inner loop (iteration over the neighbourhood) with a direct indexing (in a cython code) rather then using the slow iterator, in order to save time.
A separate issue is the new cython's parallel loop that raises the need for GIL-free numpy iterators (I might be wrong though). Anyway, it is not urgent for me. Nadav -----Original Message----- From: numpy-discussion-boun...@scipy.org [mailto:numpy-discussion-boun...@scipy.org] On Behalf Of David Cournapeau Sent: Monday, October 24, 2011 4:04 PM To: Discussion of Numerical Python Subject: Re: [Numpy-discussion] neighborhood iterator speed On Mon, Oct 24, 2011 at 1:23 PM, Nadav Horesh <nad...@visionsense.com> wrote: > * I'll try to implement the 2D iterator as far as far as my programming > expertise goes. It might take few days. I am pretty sure the code is in the history, if you are patient enough to look for it in git history. I can't remember why I removed it (maybe because it was not faster ?). > > * There is a risk in providing a buffer pointer, and for my (and probably > most) use cases it is better for the iterator constructor to provide it. I > was thinking about the possibility to give the iterator a shared memory > pointer, to open a door for multiprocessing. Maybe it is better instead to > provide a contiguous ndarray object to enable a sanity check. One could ask for an optional buffer (if NULL -> auto-allocation). But I would need a more detailed explanation about what you are trying to do to warrant changing the API here. cheers, David _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion __________ Information from ESET NOD32 Antivirus, version of virus signature database 4628 (20091122) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
