在移动的时间间隔使用python查找最大（和最小） [英] Find max(and min) on the moving interval using python

问题描述

我有一个像

[5.5, 6.0, 6.0, 6.5, 6.0, 5.5, 5.5, 5.0, 4.5]. 

此阵列的所有数字0.5不同，并且两个连续数的最大差也是0.5（它们可以是相同的;如在实施例）。并有一个移动的时间间隔，或盒子，它涵盖，例如，3个连续的数字，是这样的：

all numbers of this array differ by 0.5, and the maximum difference of two successive numbers is also 0.5(they can be same; as in the example). and there is a moving interval, or box, which covers, for example, 3 successive numbers, like this:

[(5.5, 6.0, 6.0), 6.5, 6.0, 5.5, 5.5, 5.0, 4.5]  # min: 5.5, max: 6.0

和框移动向右一个接一个：

and the box moves toward right one by one:

[5.5, (6.0, 6.0, 6.5), 6.0, 5.5, 5.5, 5.0, 4.5]  # min: 6.0, max: 6.5

[5.5, 6.0, (6.0, 6.5, 6.0), 5.5, 5.5, 5.0, 4.5]  # min: 6.0, max: 6.5

问题是，我怎么能找到的数字箱内的最小值和最大值，每次框移动？

the question is, how can I find the min and max of the numbers inside the box for each time box moves?

我可以处理它时，框和数组的大小是小像这样的例子，但我需要将此喜欢数组大小100000箱尺寸10000使用我的方法（我每次计算最大值和最小值使用循环每箱经过时间），花了太多时间（我有像100多个阵列做，需要反复运行）。有一些时间限制，所以我需要像一次计算在0.5秒运行它。

I can handle it when the size of box and array is small like this example, but I need to apply this to like array size 100000 and box size 10000. using my method(I calculate every max and min using for-loop for each time box passes), it took too much time(I have like 100 more array to do and need to run repeatedly). There is some time limit, so I need to run it like one calculation in 0.5 sec.

推荐答案

有一个看的从熊猫的滚动窗口：

Have a look at the rolling windows from pandas:

>>> import pandas as pd
>>> L = [5.5, 6.0, 6.0, 6.5, 6.0, 5.5, 5.5, 5.0, 4.5]
>>> a = pd.DataFrame(L)
>>> pd.rolling_max(a, 3)
     0
0  NaN
1  NaN
2  6.0
3  6.5
4  6.5
5  6.5
6  6.0
7  5.5
8  5.5
>>> pd.rolling_min(a, 3)
     0
0  NaN
1  NaN
2  5.5
3  6.0
4  6.0
5  5.5
6  5.5
7  5.0
8  4.5

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