我正在尝试在巨大的稀疏矩阵上应用PCA,在下面的链接中指出,sklearn的随机PCA可以处理scipy稀疏格式的稀疏矩阵。 对非常大的稀疏矩阵应用PCA
但是,我总是遇到错误。有人能指出我做错了什么吗。
输入矩阵'X_train'包含float64数字:
>>>type(X_train)
<class 'scipy.sparse.csr.csr_matrix'>
>>>X_train.shape
(2365436, 1617899)
>>>X_train.ndim
2
>>>X_train[0]
<1x1617899 sparse matrix of type '<type 'numpy.float64'>'
with 81 stored elements in Compressed Sparse Row format>
我正在尝试做:
>>>from sklearn.decomposition import RandomizedPCA
>>>pca = RandomizedPCA()
>>>pca.fit(X_train)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/home/RT11/.pyenv/versions/2.7.9/lib/python2.7/site-packages/sklearn/decomposition/pca.py", line 567, in fit
self._fit(check_array(X))
File "/home/RT11/.pyenv/versions/2.7.9/lib/python2.7/site-packages/sklearn/utils/validation.py", line 334, in check_array
copy, force_all_finite)
File "/home/RT11/.pyenv/versions/2.7.9/lib/python2.7/site-packages/sklearn/utils/validation.py", line 239, in _ensure_sparse_format
raise TypeError('A sparse matrix was passed, but dense '
TypeError: A sparse matrix was passed, but dense data is required. Use X.toarray() to convert to a dense numpy array.
如果我尝试转换为稠密矩阵,我认为内存会不够用。
>>> pca.fit(X_train.toarray())
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/home/RT11/.pyenv/versions/2.7.9/lib/python2.7/site-packages/scipy/sparse/compressed.py", line 949, in toarray
return self.tocoo(copy=False).toarray(order=order, out=out)
File "/home/RT11/.pyenv/versions/2.7.9/lib/python2.7/site-packages/scipy/sparse/coo.py", line 274, in toarray
B = self._process_toarray_args(order, out)
File "/home/RT11/.pyenv/versions/2.7.9/lib/python2.7/site-packages/scipy/sparse/base.py", line 800, in _process_toarray_args
return np.zeros(self.shape, dtype=self.dtype, order=order)
MemoryError