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Approximation algorithms for geometric median problems

Jyh-Han Lin, Jeffrey Scott Vitter
1992 Information Processing Letters  
In this paper we present approximation algorithms for median problems in metric spaces and xed-dimensional Euclidean space.  ...  Our algorithms use a new method for transforming an optimal solution of the linear program relaxation of the s-median problem into a provably good integral solution.  ...  For approximation algorithms for the s-center problem, we refer the readers to FeG,Gon, HoS  ... 
doi:10.1016/0020-0190(92)90208-d fatcat:63iziixt4ndjpjrbaati3ps6mi

Approximation schemes for Euclidean k-medians and related problems

Sanjeev Arora, Prabhakar Raghavan, Satish Rao
1998 Proceedings of the thirtieth annual ACM symposium on Theory of computing - STOC '98  
The approximation scheme also generalizes to some problems related to k-median.  ...  Our methodology is to extend Arora's [1, 2] techniques for the TSP, which hitherto seemed inapplicable to problems such as the k-median problem.  ...  algorithms for other geometric problems.  ... 
doi:10.1145/276698.276718 dblp:conf/stoc/AroraRR98 fatcat:our5vrenlndahmpnie7rqb2nti

A Multi-Objective Optimization Algorithm for Center-Based Clustering

Jared León, Boris Chullo-Llave, Lauro Enciso-Rodas, José Luis Soncco-Álvarez
2020 Electronical Notes in Theoretical Computer Science  
Also, an approximation algorithm for the discrete k -center problem is used as a local search strategy for initializing the population.  ...  Also, an approximation algorithm for the k -center problem is used as local search for generating initial solutions, that is, initial places for starting the search.  ...  The approximation problem has been widely studied for a great number of points, giving as result many polinomial time algorithms for the approximate geometric median problem.  ... 
doi:10.1016/j.entcs.2020.02.012 fatcat:zqllwpxzbbbmjgxitm23q5ghdq

Subject Index

2007 Journal of Discrete Algorithms  
polygon, 524 Sorting algorithm Asymptotic distributions for Random Median Quicksort, 592 Sorting buffers Exploiting locality: approximating sorting buffers, 729 Stable matching problem Two algorithms  ...  Character sets of strings, 330; A linear time algorithm for the inver-Label Cover Approximation algorithms for the Label-Cover MAX and Red-Blue Set Cover problems, 55 Lattice animals On the complexity  ... 
doi:10.1016/s1570-8667(07)00076-7 fatcat:wfqxglrznfb6do3wyittd5pfbi

Proportional Approval Voting, Harmonic k-median, and Negative Association

Jaroslaw Byrka, Piotr Skowron, Krzysztof Sornat, Michael Wagner
2018 International Colloquium on Automata, Languages and Programming  
To the best of our knowledge this is the first constant factor approximation algorithm for a variant of k-median that does not require this assumption.  ...  ACM Subject Classification Theory of computation → Approximation algorithms analysis  ...  Indeed, the (2.675 + )-approximation algorithm for k-median [5] , the 93-approximation algorithm for Fault Tolerant k-median [17] , the 2-approximation algorithm for k-center [18] , and the 6.357-approximation  ... 
doi:10.4230/lipics.icalp.2018.26 dblp:conf/icalp/ByrkaSS18 fatcat:ij4ywi47pjf6togjdvlng4b7wu

Weber's problem on the Riemannian Manifolds: Some upper bounds for the minimun Weber's function
El problema de Weber sobre variedades Riemannianas: Algunas cotas Superiores para el mínimo de la función de Weber

Franco Rubio, Patricia Alvarez, Heyssen Dueñes
2019 Selecciones Matemáticas  
Keywords: The Weber problem, Weighted Geometric Median, Riemannian manifold, Strongly convex set.  ...  weighted geometric median of "m" given points in the strongly convex.  ...  Case Figure 3 . 3 The red point is the geometric median for 20 points. Table 2.  ... 
doi:10.17268/sel.mat.2019.01.13 fatcat:4fqdkhzq45dsbiozq3ogp5av7a

Algorithms for dynamic geometric problems over data streams

Piotr Indyk
2004 Proceedings of the thirty-sixth annual ACM symposium on Theory of computing - STOC '04  
Acknowledgments: The author would like to thank Graham Cormode, Sudipto Guha and Muthu Muthukrishnan, for helpful discussions.  ...  This gives us a bicriterion [O(log ∆), 1 + ]-approximate algorithm for the k-median problem. The time to construct the medians is still Ω(∆ 2 ).  ...  We provide a novel algorithm for this problem. Finally, the quantity needed for the k-median problem can be computed using a variant of an algorithm for the heavy-hitters problem as in [9] .  ... 
doi:10.1145/1007352.1007413 dblp:conf/stoc/Indyk04 fatcat:nky6vxbnkneutjopnprhlqhcgy

SOMICA and geometric ICA

F.J. Theis, C.G. Puntonet, E.W. Lang
2003 Sixth International Conference of Information Fusion, 2003. Proceedings of the  
In this paper we use this fact and present a new geometric ICA algorithm that uses a SOM for learning.  ...  The separation qualiry is better in comparison to other geometric algorithms, but the computational cost is highe,: Furthermore. this new algorithm will pmvide insight in how to transfer theoretical results  ...  Conclusion We presented a new algorithm for linear ICA similar to geometric ICA using a SOM for the mixture space approximation.  ... 
doi:10.1109/icif.2003.177411 fatcat:yzmsit2jsvcydmyvuktnkyphne

The Flag Median and FlagIRLS [article]

Nathan Mankovich, Emily King, Chris Peterson, Michael Kirby
2022 arXiv   pre-print
., mean and median) for a dataset is central to a number of common machine learning algorithms.  ...  The flag median is compared the other leading algorithms for computing prototypes on the Grassmannian, namely, the ℓ_2-median and to the flag mean.  ...  An iterative algorithm for approximating a geometric median is the Weiszfeld algorithm [1] ; each iteration of this algorithm is a weighted centroid problem.  ... 
arXiv:2203.04437v1 fatcat:egh4aamt3banvmr2efbf6e7br4

Deterministic sampling and range counting in geometric data streams

Amitabha Bagchi, Amitabh Chaudhary, David Eppstein, Michael T. Goodrich
2007 ACM Transactions on Algorithms  
We present memory-efficient deterministic algorithms for constructing epsilon-nets and epsilon-approximations of streams of geometric data.  ...  Our algorithms use only a polylogarithmic amount of memory, provided the desired approximation factors are inverse-polylogarithmic. We also include a lower bound for non-iceberg geometric queries.  ...  Muthukrishnan for helpful discussions on geometric streaming algorithms in general.  ... 
doi:10.1145/1240233.1240239 fatcat:6i5xklofj5c7fdu7ufsjambram

On k-Median clustering in high dimensions

Ke Chen
2006 Proceedings of the seventeenth annual ACM-SIAM symposium on Discrete algorithm - SODA '06  
We study approximation algorithms for k-median clustering. We obtain small coresets for k-median clustering in metric spaces as well as in Euclidean spaces.  ...  This is the first streaming algorithm, for this problem, that has space complexity with only polynomial dependency on the dimension.  ...  Acknowledgments The author thanks Sariel Har-Peled for helpful discussions on the problems studied in the paper and  ... 
doi:10.1145/1109557.1109687 fatcat:lhh4wcanrfhw5opbwkszym3ycu

Deterministic sampling and range counting in geometric data streams

Amitabha Bagchi, Amitabh Chaudhary, David Eppstein, Michael T. Goodrich
2004 Proceedings of the twentieth annual symposium on Computational geometry - SCG '04  
We present memory-efficient deterministic algorithms for constructing -nets and -approximations of streams of geometric data.  ...  We also include a lower bound for non-iceberg geometric queries.  ...  Muthukrishnan for helpful discussions on geometric streaming algorithms in general.  ... 
doi:10.1145/997817.997842 dblp:conf/compgeom/BagchiCEG04 fatcat:nhyx7iw4vjelhgbxtmftzfbsqu

Clustering on Sliding Windows in Polylogarithmic Space

Vladimir Braverman, Harry Lang, Keith Levin, Morteza Monemizadeh, Marc Herbstritt
2015 Foundations of Software Technology and Theoretical Computer Science  
In PODS 2003, Babcock, Datar, Motwani and O'Callaghan [4] gave the first streaming solution for the k-median problem on sliding windows using O( k τ 4 W 2τ log 2 W) space, with a O(2 O(1/τ) ) approximation  ...  In particular, we give the first polylogarithmic space (α, β)approximation for metric k-median clustering in the sliding window model, where α and β are constants, under the assumption, also made by Babcock  ...  We say an algorithm A is an (α, β)-approximation algorithm for the k-median problem on a point set P ⊂ X if A(P, k) returns a set C ⊂ P of at most β · k centers whose cost is α-approximation of OPT(P,  ... 
doi:10.4230/lipics.fsttcs.2015.350 dblp:conf/fsttcs/BravermanLLM15 fatcat:2tly3cxflfdgxltbthhmka234y

Byzantine-Robust Federated Linear Bandits [article]

Ali Jadbabaie, Haochuan Li, Jian Qian, Yi Tian
2022 arXiv   pre-print
We propose a novel algorithm with a robust aggregation oracle that utilizes the geometric median.  ...  Finally, if the level of corruption is known to be small, we show that using the geometric median of mean oracle for robust aggregation further improves the regret bound.  ...  Of all these methods, we focus on geometric median and geometric median of mean for aggregation. Also, ǫ-approximation of the two values are considered for tractability [Pillutla et al., 2019] .  ... 
arXiv:2204.01155v1 fatcat:64deqod4xfcmnbj34jtybxvzpa

MAC Advice for Facility Location Mechanism Design [article]

Zohar Barak, Anupam Gupta, Inbal Talgam-Cohen
2024 arXiv   pre-print
We show that the 1-median (geometric median) of a set of points is naturally robust under corruptions, which leads to an algorithm for single-facility location with MAC predictions.  ...  However, these predictions are only "mostly" and "approximately" correct (or MAC for short) – i.e., some δ-fraction of the predicted locations are allowed to be arbitrarily incorrect, and the remainder  ...  Acknowledgements We are grateful to Batya Berzack for comments on an earlier draft of the paper.  ... 
arXiv:2403.12181v1 fatcat:dp5f5ljnejgs7ehdi6iwunz5uy
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