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Open questions concerning Weiszfeld’s algorithm for the Fermat-Weber location problem. (English) Zbl 0683.90026
Summary: The Fermat-Weber location problem is to find a point in ${ℝ}^{n}$ that minimizes the sum of the weighted Euclidean distances from given points in ${ℝ}^{n}$. A popular iterative solution method for this problem was first introduced by E. Weiszfeld [Tôhoku Math. J. 43, 355-386 (1937; Zbl 0017.18007)]. H. W. Kuhn [Math. Program. 4, 98-107 (1973; Zbl 0255.90063)] claimed that if the given points are not collinear then for all but a denumerable number of starting points the sequence of iterates generated by Weiszfeld’s scheme converges to the unique optimal solution. We demonstrate that Kuhn’s convergence theorem is not always correct. We then conjecture that if this algorithm is initiated at the affine subspace spanned by the given points, the convergence is ensured for all but a denumerable number of starting points.

##### MSC:
 90B85 Continuous location
##### References:
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