Question

我有以下MATLAB代码，我想用Python复制。

MATLAB代码为string[] formats= {"M/d/yyyy h:mm:ss tt", "M/d/yyyy h:mm tt", "MM/dd/yyyy hh:mm:ss", "M/d/yyyy h:mm:ss", "M/d/yyyy hh:mm tt", "M/d/yyyy hh tt", "M/d/yyyy h:mm", "M/d/yyyy h:mm", "MM/dd/yyyy hh:mm", "M/dd/yyyy hh:mm"}; string[] dateStrings = {"5/1/2009 6:32 PM", "05/01/2009 6:32:05 PM", "5/1/2009 6:32:00", "05/01/2009 06:32", "05/01/2009 06:32:00 PM", "05/01/2009 06:32:00"}; DateTime dateValue; foreach (string dateString in dateStrings) { if (DateTime.TryParseExact(dateString, formats, new CultureInfo("en-US"), DateTimeStyles.None, out dateValue)) Console.WriteLine("Converted '{0}' to {1}.", dateString, dateValue); else Console.WriteLine("Unable to convert '{0}' to a date.", dateString); }时创建逻辑数组，然后使用该逻辑数组从xDiff == 2数组中提取相应的值，以创建结果数组tDiff。

MATLAB代码：

tTacho

Answer 1

你可以用NumPy做boolean indexing 例如：

import numpy as np

x_diff = np.array([0, 2, 2, 0, 0, 2])
t_diff = np.array([0, 1, 2, 3, 4, 5])

print(t_diff[x_diff == 2])

给出：

array([1, 2, 5])

如果您不想使用NumPy，则可以将list comprehensions与zip一起使用：

x_diff = [0, 2, 2, 0, 0, 2]
t_diff = [0, 1, 2, 3, 4, 5]

print([t for t, x in zip(t_diff, x_diff) if x == 2])

给出：

[1, 2, 5]

Answer 2

您也可以使用列表索引。

 tDiff=[1,2,4,5,6,6,7]
 xDiff=[2,3,2,2,2,2,2]
 for x in range(0,len(xDiff)):
     if xDiff[x]==2:
        print tDiff[x]

如果这有帮助。

使用逻辑数组从数组中提取值

2 个答案: