NDLI: Wavelet Trees: From Theory to Practice

Content Provider	IEEE Xplore Digital Library
Author	Grossi, R. Vitter, J.S. Bojian Xu
Copyright Year	2011
Abstract	The \emph{wavelet tree} data structure is a space-efficient technique for rank and select queries that generalizes from binary characters to an arbitrary multicharacter alphabet. It has become a key tool in modern full-text indexing and data compression because of its capabilities in compressing, indexing, and searching. We present a comparative study of its practical performance regarding a wide range of options on the dimensions of different coding schemes and tree shapes. Our results are both theoretical and experimental: (1)~We show that the run-length $\delta$ coding size of wavelet trees achieves the 0-order empirical entropy size of the original string with leading constant 1, when the string's 0-order empirical entropy is asymptotically less than the logarithm of the alphabet size. This result complements the previous works that are dedicated to analyzing run-length $\gamma$-encoded wavelet trees. It also reveals the scenarios when run-length $\delta$ encoding becomes practical. (2)~We introduce a full generic package of wavelet trees for a wide range of options on the dimensions of coding schemes and tree shapes. Our experimental study reveals the practical performance of the various modifications.
Starting Page	210
Ending Page	221
File Size	395114
Page Count	12
File Format	PDF
ISBN	9781457714580
DOI	10.1109/CCP.2011.16
Language	English
Publisher	Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Publisher Date	2011-06-21
Publisher Place	Italy
Access Restriction	Subscribed
Rights Holder	Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Subject Keyword	Shape Full-text indexing Data compression Vegetation Bismuth Encoding Entropy Arrays Wavelet tree Pattern matching Indexing
Content Type	Text
Resource Type	Article

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