[Numpy-discussion] ndarray with double comparison

Marc Shivers marc.shivers@gmail....
Thu Oct 13 11:50:12 CDT 2011


you could use bitwise comparison with paretheses:

In [8]: (a>4)&(a<8)
Out[8]:
array([False, False, False, False, False,  True,  True,  True, False,
       False, False], dtype=bool)

On Thu, Oct 13, 2011 at 12:13 PM, Chao YUE <chaoyuejoy@gmail.com> wrote:

> Dear all,
>
> sorry for this stupid question but I cannot find it in numpy tutorial or
> google.
> suppose I have a=np.arange(11).
>
> In [32]: a < 8
> Out[32]:
> array([ True,  True,  True,  True,  True,  True,  True,  True, False,
>        False, False], dtype=bool)
>
> In [34]: a > 4
> Out[34]:
> array([False, False, False, False, False,  True,  True,  True,  True,
>         True,  True], dtype=bool)
>
> how can I have boolean index like 4 < a < 8
> np.where(a>4 and a<8);or plainly input "a>4 and a<8" doesn't work.
>
> thanks,
>
> Chao
>
> --
>
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