Re: [Numpy-discussion] optimise operation in array with datetime objects

2009-01-28 Thread Pierre GM
On Jan 28, 2009, at 5:43 PM, Timmie wrote: >> >> You could try: >> np.fromiter((_.hour for _ in dates_li), dtype=np.int) >> or >> np.array([_.hour for _ in dates_li], dtype=np.int) > > I used dates_li only for the preparation of example data. > > So let's suppose I have the array "dates_array" ret

Re: [Numpy-discussion] optimise operation in array with datetime objects

2009-01-28 Thread Pierre GM
On Jan 28, 2009, at 3:56 PM, Timmie wrote: > ### this is the loop I would like to optimize: > ### looping over arrays is considered inefficient. > ### what could be a better way? > hours_array = dates_array.copy() > for i in range(0, dates_array.size): > hours_array[i] = dates_array[i].hour

[Numpy-discussion] optimise operation in array with datetime objects

2009-01-28 Thread Timmie
Hello, I have an array of datetime objects. What is the most efficient way of creating a new array with only the hours or minutes out of it? Here is an example: ### imports import numpy as np import datetime as dt ### create some data d = dt.datetime.now() dates_li = [] count = 0 for i in ran