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Physical Sciences and Mathematics Commons™

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Computer Sciences

Series

2001

Measurement

Articles 1 - 2 of 2

Full-Text Articles in Physical Sciences and Mathematics

Fast Implementation Of Depth Contours Using Topological Sweep, Kim Miller, Suneeta Ramaswami, Peter Rousseeuw, Toni Sellarès, Diane Souvaine, Ileana Streinu, Anja Struyf Dec 2001

Fast Implementation Of Depth Contours Using Topological Sweep, Kim Miller, Suneeta Ramaswami, Peter Rousseeuw, Toni Sellarès, Diane Souvaine, Ileana Streinu, Anja Struyf

Computer Science: Faculty Publications

The concept of location depth was introduced in statistics as a way to extend the univariate notion of ranking to a bivariate configuration of data points. It has been used successfully for robust estimation, hypothesis testing, and graphical display. These reguire the computation of depth regions, which form a collection of nested polygons. The center of the deepest region is called the Tukey median. The only available implemented algorithms for the depth contours and the Tukey median are slow, which limits their usefulness. In this paper we describe an optimal algorithm which computes all depth contours in &Ogr;(n 2) time …

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Using Types To Analyze And Optimize Object-Oriented Programs, Amer Diwan, Kathryn S. Mckinley, J. Eliot B. Moss Jan 2001

Using Types To Analyze And Optimize Object-Oriented Programs, Amer Diwan, Kathryn S. Mckinley, J. Eliot B. Moss

Computer Science Department Faculty Publication Series

Object-oriented programming languages provide many software engineering benefits, but these often come at a performance cost. Object-oriented programs make extensive use of method in- vocations and pointer dereferences, both of which are potentially costly on modern machines. We show how to use types to produce effective, yet simple, techniques that reduce the costs of these features in Modula-3, a statically typed, object-oriented language. Our compiler performs type-based alias analysis to disambiguate memory references. It uses the results of the type-based alias analysis to eliminate redundant memory references and to replace monomorphic method in- vocation sites with direct calls. Using limit, …

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