We present a randomized algorithm for estimating thep th momentFp of the frequency vector of a data stream in the general update (turnstile) model to within a multiplicative factor of1±ϵ , forp>2 , with high constant confidence. For0<ϵ≤1 , the algorithm uses spaceO(n1−2/pϵ−2+n1−2/pϵ−4/plog(n)) words. This improves over the current bound ofO(n1−2/pϵ−2−4/plog(n)) words by Andoni et. al. in \cite{ako:arxiv10}. Our space upper bound matches the lower bound of Li and Woodruff \cite{liwood:random13} forϵ=(log(n))−Ω(1) and the lower bound of Andoni et. al. \cite{anpw:icalp13} forϵ=Ω(1) .
Pages
▼
No comments:
Post a Comment