我希望将数据框中的一列缩放到0和1之间的值。为此,我使用了一个MinMaxScaler
,它可以很好地工作,但是让我有些犹豫。我正在这样做:
x = df['Activity'].values #returns a numpy array
min_max_scaler = preprocessing.MinMaxScaler()
x_scaled = min_max_scaler.fit_transform(x)
df['Activity'] = pd.Series(x_scaled)
这段代码的第一条信息是一个警告:
DeprecationWarning: 0.17版本已经弃用将1d数组作为数据传递,0.19版本将会引发ValueError错误。如果您的数据只有一个特征,请使用X.reshape(-1,1)来调整数据格式;如果它只包含一个样本,请使用X.reshape(1,-1)。
显然,以后将不再支持1d数组,因此让我们按照建议进行调整:
x = df['Activity'].values.reshape(-1, 1)
现在代码甚至无法运行:
异常:数据必须是一维的
被抛出。所以我很困惑。1d即将被弃用,但数据也必须是1d?如何安全地解决这个问题?这里有什么问题?根据@sascha的要求进行编辑:
x
看起来像这样:array([ 0.00568953, 0.00634314, 0.00718003, ..., 0.01976002,
0.00575024, 0.00183782])
重塑后:
array([[ 0.00568953],
[ 0.00634314],
[ 0.00718003],
...,
[ 0.01976002],
[ 0.00575024],
[ 0.00183782]])
整个警告:
/usr/local/lib/python3.5/dist-packages/sklearn/preprocessing/data.py:321: DeprecationWarning: Passing 1d arrays as data is deprecated in 0.17 and will raise ValueError in 0.19. Reshape your data either using X.reshape(-1, 1) if your data has a single feature or X.reshape(1, -1) if it contains a single sample.
warnings.warn(DEPRECATION_MSG_1D, DeprecationWarning)
/usr/local/lib/python3.5/dist-packages/sklearn/preprocessing/data.py:356: DeprecationWarning: Passing 1d arrays as data is deprecated in 0.17 and will raise ValueError in 0.19. Reshape your data either using X.reshape(-1, 1) if your data has a single feature or X.reshape(1, -1) if it contains a single sample.
warnings.warn(DEPRECATION_MSG_1D, DeprecationWarning)
当我进行重塑时出现错误:
---------------------------------------------------------------------------
Exception Traceback (most recent call last)
<ipython-input-132-df180aae2d1a> in <module>()
2 min_max_scaler = preprocessing.MinMaxScaler()
3 x_scaled = min_max_scaler.fit_transform(x)
----> 4 telecom['Activity'] = pd.Series(x_scaled)
/usr/local/lib/python3.5/dist-packages/pandas/core/series.py in __init__(self, data, index, dtype, name, copy, fastpath)
225 else:
226 data = _sanitize_array(data, index, dtype, copy,
--> 227 raise_cast_failure=True)
228
229 data = SingleBlockManager(data, index, fastpath=True)
/usr/local/lib/python3.5/dist-packages/pandas/core/series.py in _sanitize_array(data, index, dtype, copy, raise_cast_failure)
2918 elif subarr.ndim > 1:
2919 if isinstance(data, np.ndarray):
-> 2920 raise Exception('Data must be 1-dimensional')
2921 else:
2922 subarr = _asarray_tuplesafe(data, dtype=dtype)
Exception: Data must be 1-dimensional