David A. Bader
IEEE Fellow
AAAS Fellow
Professor
College of Computing
Georgia Tech
Atlanta, GA 30332


 
 

 

An Improved Randomized Selection Algorithm With an Experimental Study

A common statistical problem is that of finding the median element in a set of data. This paper presents an efficient randomized high-level parallel algorithm for finding the median given a set of elements distributed across a parallel machine. In fact, our algorithm solves the general selection problem that requires the determination of the element of rank $k$, for an arbitrarily given integer $k$. Our general framework is an SPMD distributed memory programming model that is enhanced by a set of communication primitives. We use efficient techniques for distributing and coalescing data as well as efficient combinations of task and data parallelism. The algorithms have been coded in the message passing standard MPI, and our experimental results from the IBM SP-2 illustrate the scalability and efficiency of our algorithm and improve upon all the related experimental results known to the authors.

Publication History

Versions of this paper appeared as:
  1. University of New Mexico AHPCC-TR-99-014
  2. Revised version of University of New Mexico AHPCC-TR-99-014
  3. D.A. Bader, ``An Improved Randomized Selection Algorithm With an Experimental Study,'' presented at the Second Workshop on Algorithm Engineering and Experiments (ALENEX00), San Francisco, CA, January 2000.
  4. D.A. Bader, ``An Improved Randomized Selection Algorithm With an Experimental Study,'' Journal of Parallel and Distributed Computing, 64(9):1051-1059, 2004.

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Last updated: September 8, 2004

 




Computational Biology



Parallel Computing



Combinatorics