[Numpy-discussion] using the functions nonzero and where
Christopher Barker
Chris.Barker@noaa....
Tue Apr 24 12:34:52 CDT 2007
Bill Baxter wrote:
>> In [35]: x = [ 0, 0, 0, 99, 0, 1, 5]
>> In [37]: i=nonzero(x)
>> In [38]: i
>> Out[38]: (array([3, 5, 6]),)
> Just do i[0]. It's an array, not a string. Try typing "type(i[0])"
> and see what it tells you.
Which still begs the question: why does nonzero() return a tuple with an
array in it, rather than just the array?
Is it so you can so this?
>>> a = numpy.array(((3,0,4),(5,21,0)))
>>> numpy.nonzero(a)
(array([0, 0, 1, 1]), array([0, 2, 0, 1]))
>>> a[numpy.nonzero(a)]
array([ 3, 4, 5, 21])
-Chris
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Christopher Barker, Ph.D.
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