Numeric array equivalent of index ?

[Nicolas Pernetty]

Hello,

I'm trying to find a clear and fast equivalent to the index method of
plain python list :[color=blue][color=green]
>> a = [5,1,4,3,4]
>> a.index(4)[/color][/color]
2

I have to use it on a Numeric array, so the best I've come up with is
(rather ugly I think) :[color=blue][color=green]
>> from Numeric import array, equal, nonzero
>> a = array([5,1,4,3,4])
>> nonzero(equal(a ,4))[0][/color][/color]
2


Does someone know of a more Pythonic way ?

Thanks,

[Robert Kern]

Re: Numeric array equivalent of index ?

Nicolas Pernetty wrote:[color=blue]
> Hello,
>
> I'm trying to find a clear and fast equivalent to the index method of
> plain python list :
>[color=green][color=darkred]
>>>a = [5,1,4,3,4]
>>>a.index(4)[/color][/color]
>
> 2
>
> I have to use it on a Numeric array, so the best I've come up with is
> (rather ugly I think) :
>[color=green][color=darkred]
>>>from Numeric import array, equal, nonzero
>>>a = array([5,1,4,3,4])
>>>nonzero(equa l(a,4))[0][/color][/color]
>
> 2
>
> Does someone know of a more Pythonic way ?[/color]

There's a list for Numeric. You'll get better answers there.

http://numeric.scipy.org/

And no, no one has bothered adding a .index() equivalent for general,
unsorted arrays.

--
Robert Kern
rkern@ucsd.edu

"In the fields of hell where the grass grows high
Are the graves of dreams allowed to die."
-- Richard Harter