de Lenn,
Sorry I assumed the nonzero would work for sparse matrices as well.
BUT! -- If the sparse matrix used is the default scipy's
sparse.lil_matrix, you just need to print out the representation
because the lil_matrix is implemented as a _sequence of non-zero
elements_ i.e. just what you n
deLenn wrote:
> Hi,
>
> Does scipy have an equivalent to Matlab's 'find' function, to list the
> indices of all nonzero elements in a sparse matrix?
You will want to ask scipy questions on the scipy list.
http://www.scipy.org/Mailing_Lists
There is no explicit interface on sparse matrix objec
Thanks for the reply.
'nonzero' deos not seem to work with sparse matrices. here is an
example:
from scipy import *
A = sparse.lil_matrix((3,3))
A[1,2] = 10
A[2,0] = -10
nonzero(A)
>>> ()
(I tried it with an ordinary matrix, and it works fine)
Cheers.
Nick Vatamaniuc wrote:
The function you might want is nonzero() or flatnonzero()
>>> from numpy import *
>>> a=array([ [1,2],[0,4] ])
>>> a
array([[1, 2],
[0, 4]])
>>> flatnonzero(a)
array([0, 1, 3])
nonzero() will return the a sequence of index arrays of non zero
elements
flatnonzero() returns the non-z
