[Numpy-discussion] ndarray.count() ?
scipy at mspacek.mm.st
Thu Sep 7 15:17:58 CDT 2006
What's the most straightforward way to count, say, the number of 1s or
Trues in the array? Or the number of any integer?
I was surprised to discover recently that there isn't a count() method
as there is for Python lists. Sorry if this has been discussed already,
but I'm wondering if there's a reason for its absence.
I came across a thread in March:
that talked a bit about this in terms of speed, but what about just the
convenience of having a count() method?
Looks like masked arrays have a count method, don't know much about them
Also, I understand the inaccuracies when converting between binary and
decimal floating point representations, and therefore making counting of
a specific float value in an array somewhat undefined, yet it seems to
work in Python lists:
>>> a=[1.1, 1.1, 1.2]
[1.1000000000000001, 1.1000000000000001, 1.2]
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