An Efficient Program for Many-Body Simulations (or, Cray Performance from a VAX).

Abstract

The simulation of N particles interacting in a gravitational force field is useful in astrophysics, but such simulations become costly for large N. Representing the universe as a tree structure with the particles at the leaves and internal nodes labelled with the centers of mass of their descendants allows several simultaneous attacks on the computation time required by the problem. These approaches range from algorithmic changes (replacing an O(N2) algorithm with an O(N log N) algorithm) to data structure modifications, code-tuning, and hardware modifications. The changes reduced the running time of a large problem (N = 10,000) by a factor of four hundred. This paper describes both the particular program and the methodology underlying such speedups.

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Document Details

Document Type
Technical Report
Publication Date
Mar 01, 1983
Accession Number
ADA129676

Entities

People

  • Andrew Appel

Organizations

  • Carnegie Mellon University

Tags

Communities of Interest

  • Cyber

DTIC Thesaurus Topics

  • Algorithms
  • Computations
  • Computer Programming
  • Computer Programs
  • Computer Science
  • Computers
  • Differential Equations
  • Equations
  • Mathematical Programming
  • N Body Problem
  • New York
  • Radiation
  • Simulations
  • Simulators
  • Software Development
  • Time Intervals
  • Trees (Data Structures)

Fields of Study

  • Computer science
  • Physics

Readers

  • Computational Linguistics
  • Parallel and Distributed Computing.
  • Quantum spin resonance or Electron Paramagnetic Resonance spectroscopy.

Technology Areas

  • Space