python读取matlab中的datetime

### 使用Python读取Matlab文件中的Datetime数据 为了处理来自Matlab的数据，特别是其中的时间戳或`datetime`对象，可以利用SciPy库来加载`.mat`文件，并通过Pandas或其他工具解析这些时间信息。下面展示了一个具体实例： #### 加载并转换Matlab的Datetime到Python 首先安装必要的包（如果尚未安装），可以通过pip完成此操作。 ```bash pip install scipy pandas numpy matplotlib ``` 接着编写一段脚本来演示如何从Matlab `.mat` 文件中提取 `datetime` 数据并将其转化为易于使用的Python格式。 ```python import scipy.io as sio import numpy as np from datetime import timedelta, datetime import pandas as pd def convert_matlab_datenum(dn): """Convert MATLAB datenum into Python datetime. Args: dn (float): A scalar representing a date in the MATLAB serial day number format. Returns: dt (datetime.datetime): Corresponding Python datetime object. Note that this conversion assumes all dates are after year 0 AD and before Oct 15, 1582, when the Gregorian calendar was introduced. For more accurate conversions involving these edge cases, additional logic would be required.[^1] """ ordinals = dn - 366 # Remove one day because MATLAB starts counting days from Jan 0, Year 0 instead of Jan 1, Year 1 try: start = datetime.fromordinal(int(ordinals)) fractional_day = float('%.9f' % (ordinals % 1)) * 24*60*60 # Convert fraction part to seconds delta_t = timedelta(seconds=fractional_day) result_dt = start + delta_t return result_dt except ValueError: raise Exception("Invalid input value for converting MATLAB datenums.") # Load .mat file containing datetime information file_path = 'example.mat' data_dict = sio.loadmat(file_path) # Assuming there's an array named 'dates' inside example.mat which contains MATLAB datenums if isinstance(data_dict['dates'], np.ndarray): converted_dates = [convert_matlab_datenum(date_item) for date_item in data_dict['dates'].flatten()] else: converted_dates = [] # Create DataFrame with processed datetime objects df = pd.DataFrame(converted_dates, columns=['Converted_Datetime']) print(df.head()) ``` 这段代码定义了一个辅助函数`convert_matlab_datenum()`用于将MATLAB特有的datenum数值转为标准的Python `datetime` 对象。之后展示了怎样运用Scipy IO模块加载包含有日期字段的`.mat`文件，并最终创建一个带有已转换日期的新DataFrame。