python - 索引错误: indices out of the bound

Question

我正在使用 StratifiedKFold 创建用于拆分数据的索引。它给了我索引超出范围的错误。 Xdev的索引从0到47503。 cv_index 变量的 min 和 max 索引分别为 0 和 10452，那么为什么会这样错误来了？

print X_dev.shape
print Y_dev.shape
skff = StratifiedKFold(Y_dev,5)
for train_index, cv_index in skff:
    print train_index.min()
    print train_index.max()
    print cv_index.min()
    print cv_index.max()
    print train_index
    print cv_index
    print train_index.shape
    print cv_index.shape
    X_train = X_dev[cv_index]

输出

(47504, 128)
(47504,)
9049
47503
0
10452
[ 9049  9051  9054 ..., 47501 47502 47503]
[    0     1     2 ..., 10177 10242 10452]
(38000,)
(9504,)
---------------------------------------------------------------------------
IndexError                                Traceback (most recent call last)
<ipython-input-18-c911fae5d719> in <module>()
     10     print train_index.shape
     11     print cv_index.shape
---> 12     X_train = X_dev[cv_index]

/home/saurabh/anaconda/lib/python2.7/site-packages/pandas/core/frame.pyc in __getitem__(self, key)
   1789         if isinstance(key, (Series, np.ndarray, Index, list)):
   1790             # either boolean or fancy integer index
-> 1791             return self._getitem_array(key)
   1792         elif isinstance(key, DataFrame):
   1793             return self._getitem_frame(key)

/home/saurabh/anaconda/lib/python2.7/site-packages/pandas/core/frame.pyc in _getitem_array(self, key)
   1834         else:
   1835             indexer = self.ix._convert_to_indexer(key, axis=1)
-> 1836             return self.take(indexer, axis=1, convert=True)
   1837 
   1838     def _getitem_multilevel(self, key):

/home/saurabh/anaconda/lib/python2.7/site-packages/pandas/core/generic.pyc in take(self, indices, axis, convert, is_copy)
   1356         new_data = self._data.take(indices,
   1357                                    axis=self._get_block_manager_axis(axis),
-> 1358                                    convert=True, verify=True)
   1359         result = self._constructor(new_data).__finalize__(self)
   1360 

/home/saurabh/anaconda/lib/python2.7/site-packages/pandas/core/internals.pyc in take(self, indexer, axis, verify, convert)
   3264         n = self.shape[axis]
   3265         if convert:
-> 3266             indexer = maybe_convert_indices(indexer, n)
   3267 
   3268         if verify:

/home/saurabh/anaconda/lib/python2.7/site-packages/pandas/core/indexing.pyc in maybe_convert_indices(indices, n)
   1709     mask = (indices >= n) | (indices < 0)
   1710     if mask.any():
-> 1711         raise IndexError("indices are out-of-bounds")
   1712     return indices
   1713 

IndexError: indices are out-of-bounds

我添加了我认为相关的信息。如果需要更多信息来回答这个问题，请告诉我。

Answer 1

此示例适用于较低维度的数据，但我不知道为什么它不适用于此维度。所以我换行

 X_train = X_dev[cv_index]

到

X_train = X_dev.ix[cv_index]

及其工作原理。