asindices(x) 中的 scipy\sparse\csr.pyc 获取 IndexError: invalid index

Question

我正在使用 lib UnbalancedDataset 进行一些过采样。

我有 X_train_features.shape (30962, 15637) 和 y_train.shape (30962,)

type(X_train_features) 是scipy.sparse.csr.csr_matrix

获取索引错误：

IndexError                                Traceback (most recent call last)
<ipython-input-44-fa5e3a9ff626> in <module>()
      5 os = OverSampler(ratio=ratio, verbose=verbose)
      6 
----> 7 osx, osy = os.fit_transform(X_train_features, y_train)

C:\Python27\lib\site-packages\unbalanceddataset-0.1-py2.7.egg\unbalanced_dataset\unbalanced_dataset.pyc in fit_transform(self, x, y)
    260 
    261         self.fit(x, y)
--> 262         self.out_x, self.out_y = self.resample()
    263 
    264         return self.out_x, self.out_y

C:\Python27\lib\site-packages\unbalanceddataset-0.1-py2.7.egg\unbalanced_dataset\over_sampling.pyc in resample(self)
     52 
     53         # Start with the majority class
---> 54         overx = self.x[self.y == self.maxc]
     55         overy = self.y[self.y == self.maxc]
     56 

C:\Python27\lib\site-packages\scipy\sparse\csr.pyc in __getitem__(self, key)
    305             row, col = self._index_to_arrays(row, col)
    306 
--> 307         row = asindices(row)
    308         col = asindices(col)
    309         if row.shape != col.shape:

C:\Python27\lib\site-packages\scipy\sparse\csr.pyc in asindices(x)
    224                     x = x.astype(idx_dtype)
    225             except:
--> 226                 raise IndexError('invalid index')
    227             else:
    228                 return x

IndexError: invalid index

我调试到lib中，发现self.x[self.y == self.maxc]等于

X_train_features[y_train == 1]

1. 我猜这个语句是选择X_train_features中的所有y_train == 1行，不是吗？

2. 如何克服这个错误？

Answer 1

会

X_train_features[y_train == 1]

工作？对于小样本，这种索引工作：

In [225]: M=sparse.csr_matrix(np.arange(12).reshape(3,4))
In [226]: M[np.arange(3)>0]