[Numpy-discussion] Find insertion point

Nikolaus Rath Nikolaus at rath.org
Tue Aug 17 14:21:16 EDT 2010


Warren Weckesser <warren.weckesser at enthought.com> writes:
> Nikolaus Rath wrote:
>> Hello,
>>
>> I want to find the first i such that x[i] < y and x[i+1] >= y. Is there
>> a way to do this without using a Python loop?
>>
>> I can't use np.searchsorted(), because my x array crosses y several
>> times.
>>
>
> In [34]: np.where((x[:-1] < y) & (x[1:] > y))[0][0]
> Out[34]: 2

Neat, thanks!



   -Nikolaus

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