I have coo_matrix X
and indexes trn_idx
by which I would like to get access of that maxtrix
print (type(X ), X.shape)
print (type(trn_idx), trn_idx.shape)
<class 'scipy.sparse.coo.coo_matrix'> (1503424, 2795253)
<class 'numpy.ndarray'> (1202739,)
Calling this way:
X[trn_idx]
TypeError: only integer scalar arrays can be converted to a scalar index
Either this way:
X[trn_idx.astype(int)] #same error
How to access by index?
The coo_matrix
class does not support indexing. You'll have to convert it to a different sparse format.
Here's an example with a small coo_matrix
:
In [19]: import numpy as np
In [20]: from scipy.sparse import coo_matrix
In [21]: m = coo_matrix([[0, 0, 0, 1], [2, 0, 0 ,0], [0, 0, 0, 0], [0, 3, 4, 0]])
Attempting to index m
fails:
In [22]: m[0,0]
---------------------------------------------------------------------------
TypeError Traceback (most recent call last)
<ipython-input-22-1f78c188393f> in <module>()
----> 1 m[0,0]
TypeError: 'coo_matrix' object is not subscriptable
In [23]: idx = np.array([2, 3])
In [24]: m[idx]
---------------------------------------------------------------------------
TypeError Traceback (most recent call last)
<ipython-input-24-a52866a6fec6> in <module>()
----> 1 m[idx]
TypeError: only integer scalar arrays can be converted to a scalar index
If you convert m
to a CSR matrix, you can index it with idx
:
In [25]: m.tocsr()[idx]
Out[25]:
<2x4 sparse matrix of type '<class 'numpy.int64'>'
with 2 stored elements in Compressed Sparse Row format>
If you are going to do more indexing, it would be better to save the new array in a variable, and use it as needed:
In [26]: a = m.tocsr()
In [27]: a[idx]
Out[27]:
<2x4 sparse matrix of type '<class 'numpy.int64'>'
with 2 stored elements in Compressed Sparse Row format>
In [28]: a[0,0]
Out[28]: 0
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With