小编Mik*_*rev的帖子

我真的无法理解numpy.gradient函数是做什么以及如何使用它来计算多变量函数梯度.

例如,我有这样一个功能:

def func(q, chi, delta):
    return q * chi * delta

我需要计算它的三维梯度(换句话说,我想计算所有变量(q,chi,delta)的偏导数).

如何使用NumPy计算此渐变？

我有一个带有DatetimeIndex的数据框。这是列之一：

>>> y.out_brd
2013-01-01 11:25:00     0.04464286
2013-01-01 11:30:00            NaN
2013-01-01 11:35:00            NaN
2013-01-01 11:40:00    0.005952381
2013-01-01 11:45:00     0.01785714
2013-01-01 11:50:00    0.008928571
Freq: 5T, Name: out_brd, dtype: object

当我尝试interpolate()在函数上使用时，我绝对不会改变：

>>> y.out_brd.interpolate(method='time')
2013-01-01 11:25:00     0.04464286
2013-01-01 11:30:00            NaN
2013-01-01 11:35:00            NaN
2013-01-01 11:40:00    0.005952381
2013-01-01 11:45:00     0.01785714
2013-01-01 11:50:00    0.008928571
Freq: 5T, Name: out_brd, dtype: object

如何使其运作？

更新：用于生成此类数据框的代码。

time_index = pd.date_range(start=datetime(2013, 1, 1, 3),
                       end=datetime(2013, 1, 2, 2, 59),
                       freq='5T')
grid_columns = [u'in_brd', u'in_alt', u'out_brd', u'out_alt']                           

df = pd.DataFrame(index=time_index, columns=grid_columns) …

我正在尝试编写Schedule类,其中包含这样的记录:... session,base,engine declaration at here ...

class Schedule(Base):
    __tablename__ = 'schedule'
    id = Column(Integer, primary_key=True)
    # and here i need ref to Station class
    station_id = Column(Integer, ForeignKey('station.id'))
    station = relationship('Station') # Also tried Station
    arr_time = Column(Time)

    def __init__(self, station_name, arrive_time):
         self.metadata.create_all()
         self.arrive_time = arrive_time

         # And now I'm trying to find station object by a given name
         # and add ref to it in self.station. 
         # The selection of a station works properly here:
         station = session.query(Station).filter(Station.name == …

我在Mac上使用Visual Studio代码作为python IDE,一切都适合我.但几周前我开始使用Windows.突然间,我无法在我在Mac上启动的项目中使用pylint.

我有

• 显式激活pylintEnabled选项(= True)
• 已设置pylint.exe的完整路径("c:\ Anaconda 3 ...")
• pylintrc 初始挂钩的文件将项目添加到根目录中的pythonpath(由pylint使用--generate-rcfile生成).

使用相同的参数,在Linux(Ubuntu 16.10)和Mac上一切正常.并不适用于两台Windows机器.似乎pylint不会运行.

我哪里做错了？

更新:

我发现pylint正在获取UnicodeDecodingError:

##########Linting Output - pylint##########

Traceback (most recent call last):
  File "C:\Program Files\Anaconda3\Scripts\pylint-script.py", line 5, in <module>
    sys.exit(pylint.run_pylint())
  File "C:\Program Files\Anaconda3\lib\site-packages\pylint\__init__.py", line 13, in run_pylint
    Run(sys.argv[1:])
  File "C:\Program Files\Anaconda3\lib\site-packages\pylint\lint.py", line 1264, in __init__
    linter.read_config_file()
  File "C:\Program Files\Anaconda3\lib\site-packages\pylint\config.py", line 627, in read_config_file
    parser.readfp(fp)
  File "C:\Program Files\Anaconda3\lib\configparser.py", line 760, in readfp
    self.read_file(fp, source=filename)
  File "C:\Program Files\Anaconda3\lib\configparser.py", line 715, in read_file
    self._read(f, source)
  File "C:\Program Files\Anaconda3\lib\configparser.py", line …