【问题标题】:Reshaping array using array.reshape(-1, 1)使用 array.reshape(-1, 1) 重塑数组
【发布时间】:2020-03-21 19:58:08
【问题描述】:

我有一个名为 data 的数据框,我试图从中找出任何异常价格。

数据帧头长这样:

         Date  Last Price
0  29/12/2017     487.74
1  28/12/2017     422.85
2  27/12/2017     420.64
3  22/12/2017     492.76
4  21/12/2017     403.95

我找到了一些代码,我需要针对加载数据的数据稍作调整,然后将时间序列与定标器进行比较。代码如下:

    data = pd.read_csv(path) 
    data = rawData['Last Price']

    data = data['Last Price']
    scaler = StandardScaler()
    np_scaled = scaler.fit_transform(data)
    data = pd.DataFrame(np_scaled)
    # train oneclassSVM 
    outliers_fraction = 0.01
    model = OneClassSVM(nu=outliers_fraction, kernel="rbf", gamma=0.01)
    model.fit(data)
    data['anomaly3'] = pd.Series(model.predict(data))

    fig, ax = plt.subplots(figsize=(10,6))
    a = data.loc[data['anomaly3'] == -1, ['date_time_int', 'Last Price']] #anomaly

    ax.plot(data['date_time_int'], data['Last Price'], color='blue')
    ax.scatter(a['date_time_int'],a['Last Price'], color='red')
    plt.show();

def getDistanceByPoint(data, model):
    distance = pd.Series()
    for i in range(0,len(data)):
        Xa = np.array(data.loc[i])
        Xb = model.cluster_centers_[model.labels_[i]-1]
        distance.set_value(i, np.linalg.norm(Xa-Xb))
    return distance

但是得到错误信息:

ValueError: Expected 2D array, got 1D array instead:
array=[487.74 422.85 420.64 ... 461.57 444.33 403.84].
Reshape your data either using array.reshape(-1, 1) if your data has a single feature or array.reshape(1, -1) if it contains a single sample.

我不确定我需要在哪里调整数组的大小。

有关信息,这是回溯:

 File "<ipython-input-23-628125407694>", line 1, in <module>
    runfile('C:/Users/stacey/Downloads/techJob.py', wdir='C:/Users/stacey/Downloads')

  File "C:\Anaconda_Python 3.7\2019.03\lib\site-packages\spyder_kernels\customize\spydercustomize.py", line 786, in runfile
    execfile(filename, namespace)

  File "C:\Anaconda_Python 3.7\2019.03\lib\site-packages\spyder_kernels\customize\spydercustomize.py", line 110, in execfile
    exec(compile(f.read(), filename, 'exec'), namespace)

  File "C:/Users/staceyDownloads/techJob.py", line 92, in <module>
    main()

  File "C:/Users/stacey/Downloads/techJob.py", line 56, in main
    np_scaled = scaler.fit_transform(data)

  File "C:\Anaconda_Python 3.7\2019.03\lib\site-packages\sklearn\base.py", line 464, in fit_transform
    return self.fit(X, **fit_params).transform(X)

  File "C:\Anaconda_Python 3.7\2019.03\lib\site-packages\sklearn\preprocessing\data.py", line 645, in fit
    return self.partial_fit(X, y)

  File "C:\Anaconda_Python 3.7\2019.03\lib\site-packages\sklearn\preprocessing\data.py", line 669, in partial_fit
    force_all_finite='allow-nan')

  File "C:\Anaconda_Python 3.7\2019.03\lib\site-packages\sklearn\utils\validation.py", line 552, in check_array
    "if it contains a single sample.".format(array))

ValueError: Expected 2D array, got 1D array instead:
array=[7687.77 7622.88 7620.68 ... 5261.57 5244.37 5203.89].
Reshape your data either using array.reshape(-1, 1) if your data has a single feature or array.reshape(1, -1) if it contains a single sample.

【问题讨论】:

  • Python 总是为您提供追溯问题的根源。请将其复制到您的问题中。
  • 这是您的问题。您可以在回溯中找到确切的行:File "C:/Users/stacey/Downloads/SIGtechJob.py", line 56, in main np_scaled = scaler.fit_transform(data)
  • 你明白sklearn 中的features 是什么意思吗?它对数据输入有一定的约定。研究这些是个好主意;否则你最终可能会修补你的代码,一次一个错误,而不知道为什么。

标签: python pandas numpy scikit-learn


【解决方案1】:

您应该能够通过更改此行来修复错误:

np_scaled = scaler.fit_transform(data)

用这个:

np_scaled = scaler.fit_transform(data.values.reshape(-1,1))

【讨论】:

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