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# scipy.spatial.cKDTree.query_pairs

`cKDTree.``query_pairs`(self, r, p=2., eps=0)

  Find all pairs of points whose distance is at most r.

  Parameters: | r : positive float The maximum distance. p : float, optional Which Minkowski norm to use. `p` has to meet the condition `1 <= p <= infinity`. eps : float, optional Approximate search. Branches of the tree are not explored if their nearest points are further than `r/(1+eps)`, and branches are added in bulk if their furthest points are nearer than `r * (1+eps)`. eps has to be non-negative. output_type : string, optional Choose the output container, ‘set’ or ‘ndarray’. Default: ‘set’
  Returns: | results : set or ndarray Set of pairs `(i,j)`, with `i < j`, for which the corresponding positions are close. If output_type is ‘ndarray’, an ndarry is returned instead of a set.