[Numpy-discussion] Array search considering order
andrei at ruivo.org
Thu Dec 19 11:49:38 EST 2013
On Thu, Dec 19, 2013 at 01:51:30PM +0000, Oscar Benjamin wrote:
> Date: Thu, 19 Dec 2013 13:51:30 +0000
> From: Oscar Benjamin <oscar.j.benjamin at gmail.com>
> To: Discussion of Numerical Python <numpy-discussion at scipy.org>
> Subject: Re: [Numpy-discussion] Array search considering order
> On 19 December 2013 12:51, rootspin <andrei at ruivo.org> wrote:
> > Hello,
> > Need some help in searching arrays (Im new to numpy)
> > Is it possible to search a array, using another array considering
> > order/sequence?
> > x = np.array([1,2,3,4,5,6], np.int32)
> > y = np.array([1,4,3,2,6,5], np.int32)
> > query= np.array([1,2,3],np.int32)
> > x versus query True
> > y versus query False
> > Tried with:
> > np.searchsorted(x,query) -------> array([0, 1, 2])
> > np.searchsorted(y,query) -------> array([0, 1, 4])
> I'm not sure if I understand your problem do you mean that you want to
> find subarrays of an array the same way that e.g. "in" for strings
> tests for substrings:
> >>> 'asd' in 'qweasdzxc'
> If so then perhaps this SO question has the answer you want:
> NumPy-Discussion mailing list
> NumPy-Discussion at scipy.org
Thank you Oscar for your answer.
Sorry if I was not clear enough.
The SO question is alike what I want. However, in my problem, Im not sure if there will be only one occurence.
What I do expect is:
Given one array (big one), to retrieve indexes for "query array" occurences.
Something like that:
array1(big one) - 1,2,3,4,5,6,7,1,2,3,4,5,7,8,9,1,2,3,4,5,6,7,8
array2(query) - 1,2,3
array3(another query) - 8,7,6
result (array1 versus array2) - 0,7,15 (position for match)
result (array1 versus array3) - no matches
Thanks for the help.
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