python - Finding the indices of the rows where there are non-zero entries in a sparse csc_matrix -


i have numpy array, x:

type(x) >>> <class 'scipy.sparse.csc.csc_matrix'>

i interested in finding indices of rows there non-zero entries, in 0th column. tried:

getcol =  x.getcol(0) print getcol

which gives me:

(0, 0)  1 (2, 0)  1 (5, 0)  10

this great, want vector has 0, 2, 5 in it.

how indices i'm looking for?

thanks help.

with csc matrix can following:

>>> import scipy.sparse sps >>> = np.array([[1, 0, 0], ...               [0, 1, 0], ...               [1, 0, 1], ...               [0, 0, 1], ...               [0, 1, 0], ...               [1, 0, 1]]) >>> aa = sps.csc_matrix(a) >>> aa.indices[aa.indptr[0]:aa.indptr[1]] array([0, 2, 5]) >>> aa.indices[aa.indptr[1]:aa.indptr[2]] array([1, 4]) >>> aa.indices[aa.indptr[2]:aa.indptr[3]] array([2, 3, 5])

so aa.indices[aa.indptr[col]:aa.indptr[col+1]] should after.


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