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-zero elements of the flattened version > of the array. > > Cheers, > Nick Vatamaniuc > > > > 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? > > > > Cheers. -- http://mail.python.org/mailman/listinfo/python-list
