Functions for stride manipulations
Hey, Inspired by an existing PR into numpy, I created two functions based on stride_tricks which I thought might be useful inside numpy. So if I get any feedback/pointers, I would add some tests and create a PR. The first function rolling_window is to create for every point of the original array, a view of its neighbourhood in arbitrary dimensions with some options to make it easy to use. For example for a 3 dim array: rolling_window(a, (3,3,3), asteps=(3,3,3)).max((3,4,5)) Gives the maximum for all non-overlapping 3x3x3 subarrays and: rolling_window(a, 3, axes=0).max(-1) would create the rolling maximum over all 3 successive values along the 0th axis. Plus a function permute_axes which allows to give a tuple for switching axes and can also merge them. A (10, 4, 3) shaped array would give: permute_axes(a, (2, 1, 0)).shape -> (3, 4, 10) permute_axes(a, (1, (0, 2))).shape -> (4, 30) A copy is created when necessary, this basically allows to do multiple swap_axes and a reshape in a single call. I hope this might be useful... Regards, Sebastian
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Sebastian Berg