add multiple rows/columns in a sparse matrix scipy

Question

我有一个稀疏矩阵，我需要在其中添加多行（以块为单位），比如说1:30，然后是45:50，等等。最有效的方法是什么？

Answer 1

wouldn't sum do the job? try:

a = np.array([[1,1],
              [2,2],
              [3,3]])
>>> a[1:3]
array([[2, 2],
       [3, 3]])

>>> sum(a[1:3])
10

Edit: if you are looking to sum 'vertically'

>>> sum( a, axis=0 )
array([6, 6])