3

如果您能告诉我如何使用 SMOTENC，我将不胜感激。我写：

# Data
XX = pd.read_csv('Financial Distress.csv')
y = np.array(XX['Financial Distress'].values.tolist())
y = np.array([0 if i > -0.50 else 1 for i in y])
Na = np.array(pd.read_csv('Na.csv', header=None).values)

XX = XX.iloc[:, 3:127]

# Use get-dummies to convert categorical features into dummy ones
dis_features = ['x121']
X = pd.get_dummies(XX, columns=dis_features)

# # Divide Data into Train and Test
indices = np.arange(y.shape[0])
X_train, X_test, y_train, y_test, idx_train, idx_test = train_test_split(X, y, indices, stratify=y, test_size=0.3,
                                                                         random_state=42)
num_indices=list(X)[:X.shape[1]-37]
cat_indices=list(X)[X.shape[1]-37:]
num_indices1 = list(X.iloc[:,np.r_[0:94,95,97,100:123]].columns.values)
cat_indices1 = list(X.iloc[:,np.r_[94,96,98,99,123:160]].columns.values)
print(len(num_indices1))
print(len(cat_indices1))

pipeline=Pipeline(steps= [
    # Categorical features
    ('feature_processing', FeatureUnion(transformer_list = [
            ('categorical', MultiColumn(cat_indices)),

            #numeric
            ('numeric', Pipeline(steps = [
                ('select', MultiColumn(num_indices)),
                ('scale', StandardScaler())
                        ]))
        ])),
    ('clf', rg)
    ]
)
pipeline_with_resampling = make_pipeline(SMOTENC(categorical_features=cat_indices1), pipeline)

# # Grid Search to determine best params
cv=StratifiedKFold(n_splits=5,random_state=42)
rg_cv = GridSearchCV(pipeline_with_resampling, param_grid, cv=cv, scoring = 'f1')
rg_cv.fit(X_train, y_train)

因此，如前所述，我有 5 个分类特征。实际上，索引 123 到 160 与一个具有 37 个可能值的分类特征相关，这些值使用 get_dummies 转换为 37 列。不幸的是，它会引发以下错误：

Traceback (most recent call last):
  File "D:/mifs-master_2/MU/learning-from-imbalanced-classes-master/learning-from-imbalanced-classes-master/continuous/Final Logit/SMOTENC/logit-final - Copy.py", line 424, in <module>
    rg_cv.fit(X_train, y_train)
  File "C:\Users\Markazi.co\Anaconda3\lib\site-packages\sklearn\model_selection\_search.py", line 722, in fit
    self._run_search(evaluate_candidates)
  File "C:\Users\Markazi.co\Anaconda3\lib\site-packages\sklearn\model_selection\_search.py", line 1191, in _run_search
    evaluate_candidates(ParameterGrid(self.param_grid))
  File "C:\Users\Markazi.co\Anaconda3\lib\site-packages\sklearn\model_selection\_search.py", line 711, in evaluate_candidates
    cv.split(X, y, groups)))
  File "C:\Users\Markazi.co\Anaconda3\lib\site-packages\sklearn\externals\joblib\parallel.py", line 917, in __call__
    if self.dispatch_one_batch(iterator):
  File "C:\Users\Markazi.co\Anaconda3\lib\site-packages\sklearn\externals\joblib\parallel.py", line 759, in dispatch_one_batch
    self._dispatch(tasks)
  File "C:\Users\Markazi.co\Anaconda3\lib\site-packages\sklearn\externals\joblib\parallel.py", line 716, in _dispatch
    job = self._backend.apply_async(batch, callback=cb)
  File "C:\Users\Markazi.co\Anaconda3\lib\site-packages\sklearn\externals\joblib\_parallel_backends.py", line 182, in apply_async
    result = ImmediateResult(func)
  File "C:\Users\Markazi.co\Anaconda3\lib\site-packages\sklearn\externals\joblib\_parallel_backends.py", line 549, in __init__
    self.results = batch()
  File "C:\Users\Markazi.co\Anaconda3\lib\site-packages\sklearn\externals\joblib\parallel.py", line 225, in __call__
    for func, args, kwargs in self.items]
  File "C:\Users\Markazi.co\Anaconda3\lib\site-packages\sklearn\externals\joblib\parallel.py", line 225, in <listcomp>
    for func, args, kwargs in self.items]
  File "C:\Users\Markazi.co\Anaconda3\lib\site-packages\sklearn\model_selection\_validation.py", line 528, in _fit_and_score
    estimator.fit(X_train, y_train, **fit_params)
  File "C:\Users\Markazi.co\Anaconda3\lib\site-packages\imblearn\pipeline.py", line 237, in fit
    Xt, yt, fit_params = self._fit(X, y, **fit_params)
  File "C:\Users\Markazi.co\Anaconda3\lib\site-packages\imblearn\pipeline.py", line 200, in _fit
    cloned_transformer, Xt, yt, **fit_params_steps[name])
  File "C:\Users\Markazi.co\Anaconda3\lib\site-packages\sklearn\externals\joblib\memory.py", line 342, in __call__
    return self.func(*args, **kwargs)
  File "C:\Users\Markazi.co\Anaconda3\lib\site-packages\imblearn\pipeline.py", line 576, in _fit_resample_one
    X_res, y_res = sampler.fit_resample(X, y, **fit_params)
  File "C:\Users\Markazi.co\Anaconda3\lib\site-packages\imblearn\base.py", line 85, in fit_resample
    output = self._fit_resample(X, y)
  File "C:\Users\Markazi.co\Anaconda3\lib\site-packages\imblearn\over_sampling\_smote.py", line 940, in _fit_resample
    self._validate_estimator()
  File "C:\Users\Markazi.co\Anaconda3\lib\site-packages\imblearn\over_sampling\_smote.py", line 933, in _validate_estimator
    ' should be between 0 and {}'.format(self.n_features_))
ValueError: Some of the categorical indices are out of range. Indices should be between 0 and 160

提前致谢。

4

3 回答 3

2

如下所示，应使用两条管道：

num_indices1 = list(X.iloc[:,np.r_[0:94,95,97,100:120,121:123]].columns.values)
cat_indices1 = list(X.iloc[:,np.r_[94,96,98,99,120]].columns.values)
print(len(num_indices1))
print(len(cat_indices1))
cat_indices = [94, 96, 98, 99, 120]

from imblearn.pipeline import make_pipeline

pipeline=Pipeline(steps= [
    # Categorical features
    ('feature_processing', FeatureUnion(transformer_list = [
            ('categorical', MultiColumn(cat_indices1)),

            #numeric
            ('numeric', Pipeline(steps = [
                ('select', MultiColumn(num_indices1)),
                ('scale', StandardScaler())
                        ]))
        ])),
    ('clf', rg)
    ]
)
pipeline_with_resampling = make_pipeline(SMOTENC(categorical_features=cat_indices), pipeline)
于 2019-10-25T13:54:27.563 回答
1

您不能模拟您的分类变量并在以后使用 SMOTENC，因为它已经在其算法 get_dummies 中实现了会使您的模型产生偏差的内容。但是，我建议使用 SMOTE() 而不是 SMOTENC()，但在这种情况下，您必须先应用 get_demmies。

于 2019-08-09T07:56:19.243 回答
0

您不能将 scikit 学习管道与 imblearn 管道一起使用。imblearn 管道实现了 fit_sample 和 fit_predict。Sklearn 管道仅实现 fit_predict。你不能把它们结合起来。

于 2021-02-24T16:33:36.923 回答