NumPy和SciPy - .todense()和.toarray()之间的区别

Question

我想知道在稀疏的NumPy数组上使用.toarray()vs. 是否有任何差异(优点/缺点).todense().例如,

import scipy as sp
import numpy as np
sparse_m = sp.sparse.bsr_matrix(np.array([[1,0,0,0,1], [1,0,0,0,1]]))

%timeit sparse_m.toarray()
1000 loops, best of 3: 299 µs per loop

%timeit sparse_m.todense()
1000 loops, best of 3: 305 µs per loop

Answer 1

toarray返回一个ndarray; todense返回一个矩阵.如果你想要一个矩阵,请使用todense; 否则,使用toarray.