平均日期数组计算

Question

我想得到以下日期的平均值.我考虑过将所有数据转换为秒,然后对它们求平均值.但是可能有更好的方法.

date = ['2016-02-23 09:36:26', '2016-02-24 10:00:32', '2016-02-24 11:28:22', '2016-02-24 11:27:20', '2016-02-24 11:24:15', '2016-02-24 11:20:25', '2016-02-24 11:17:43', '2016-02-24 11:12:03', '2016-02-24 11:09:11', '2016-02-24 11:08:44', '2016-02-24 11:05:28', '2016-02-24 11:03:23', '2016-02-24 10:58:08', '2016-02-24 10:53:59', '2016-02-24 10:49:34', '2016-02-24 10:43:33', '2016-02-24 10:35:27', '2016-02-24 10:31:50', '2016-02-24 10:31:17', '2016-02-24 10:30:05', '2016-02-24 10:29:21']

讨厌的解决方案:

import datetime
import time
import numpy as np

date = ['2016-02-23 09:36:26', '2016-02-24 10:00:32', '2016-02-24 11:28:22', '2016-02-24 11:27:20', '2016-02-24 11:24:15', '2016-02-24 11:20:25', '2016-02-24 11:17:43', '2016-02-24 11:12:03', '2016-02-24 11:09:11', '2016-02-24 11:08:44', '2016-02-24 11:05:28', '2016-02-24 11:03:23', '2016-02-24 10:58:08', '2016-02-24 10:53:59', '2016-02-24 10:49:34', '2016-02-24 10:43:33', '2016-02-24 10:35:27', '2016-02-24 10:31:50', '2016-02-24 10:31:17', '2016-02-24 10:30:05', '2016-02-24 10:29:21']
sec = [time.mktime(datetime.datetime.strptime(d, "%Y-%m-%d %H:%M:%S").timetuple()) for d in date]
mean = datetime.datetime.fromtimestamp(np.mean(sec))
print(mean)

Answer 1

在NumPy中,所有datetime64[s]内部都由8字节整数表示.整数表示自纪元以来的秒数.

因此,您可以将date列表转换为datetime64[s]dtype 的NumPy数组,将其视为dtype i8(8字节整数),取平均值,然后将int转换回a datetime64[s].

import numpy as np

date = ['2016-02-23 09:36:26', '2016-02-24 10:00:32', '2016-02-24 11:28:22', '2016-02-24 11:27:20', '2016-02-24 11:24:15', '2016-02-24 11:20:25', '2016-02-24 11:17:43', '2016-02-24 11:12:03', '2016-02-24 11:09:11', '2016-02-24 11:08:44', '2016-02-24 11:05:28', '2016-02-24 11:03:23', '2016-02-24 10:58:08', '2016-02-24 10:53:59', '2016-02-24 10:49:34', '2016-02-24 10:43:33', '2016-02-24 10:35:27', '2016-02-24 10:31:50', '2016-02-24 10:31:17', '2016-02-24 10:30:05', '2016-02-24 10:29:21']

mean = (np.array(date, dtype='datetime64[s]')
        .view('i8')
        .mean()
        .astype('datetime64[s]'))

print(mean)

版画

2016-02-24T09:43:40-0500