617.txt

来自「This complete matlab for neural network」· 文本 代码 · 共 39 行

发信人: lionprince (狮子王子), 信区: DataMining
标  题: Re: 关联规则的一种算法
发信站: 南京大学小百合站 (Mon Dec 30 20:01:54 2002)

粗粗浏览了一下，摘抄几个要点：
The bottom-up search starts from frequent 1-itemsets (the minimum length
frequent itemsets) and continues until all maximal (length) frequent itemset
s are found. During the execution, every
frequent itemset is explicitly considered. Such algorithms perform well when
 all maximal frequent itemsets are
short.
The top-down search starts with the single n-itemset and decreases the size 
of the candidates by one in every
pass. Such algorithms perform well when all maximal frequent itemsets are lo
ng.
We present a new algorithm which combines both the bottom-up and the top-dow
n searches. The primary search
direction is still bottom-up, but a restricted search is also conducted in t
he top-down direction.
简单说，bottom-up适用于最大频繁项集为短的情况，top-down适用于最大频繁项集为长
的情况，而Pincer search则综合了2种方法，适用于一些最大频繁项集短最大频繁项集
长的情况

【 在 GzLi (笑梨) 的大作中提到: 】
: lionprince已经上传到
: ftp://211.80.38.17/DataMining/paper/dm%20artical/
: Pincer Search(lionprince??).pdf
: thanks to lionprince!
: 【 在 lionprince (狮子王子) 的大作中提到: 】
: : Pincer-Search：It's a new algorithm which combines both the bottom-up and..
: :  top-down searches.
: : 有没有谁看过这篇论文
: : Pincer-Search: An Efficient Algorithm for Discovering the Maximum Frequen..
: : 对这种算法有何看法？


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