“大数据算法”版本间的差异
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研究论文： | 研究论文： | ||
# Vigna, Sebastiano. "Broadword implementation of rank/select queries." In International Workshop on Experimental and Efficient Algorithms, WEA 2008. | # Vigna, Sebastiano. "Broadword implementation of rank/select queries." In International Workshop on Experimental and Efficient Algorithms, WEA 2008. | ||
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| − | * [ | + | 基数估计（Cardinality Estimation），评估一个集合中不同数据项的个数的近似算法。比如，访问一个网站的独立IP个数。 |
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| + | * [https://github.com/Microsoft/CardinalityEstimation Cardinality Estimation Algorithm] | ||
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| + | # Flajolet, Philippe, Éric Fusy, Olivier Gandouet, and Frédéric Meunier. "Hyperloglog: the analysis of a near-optimal cardinality estimation algorithm." DMTCS Proceedings 1 (2008). | ||
| + | # Heule, Stefan, Marc Nunkesser, and Alexander Hall. "HyperLogLog in practice: algorithmic engineering of a state of the art cardinality estimation algorithm." In Proceedings of the 16th International Conference on Extending Database Technology, pp. 683-692. ACM, 2013. | ||
2017年5月14日 (日) 03:10的版本
数据分析
数据分析（Data Analytic），是指对数据集DataSet的属性值进行统计，以发现有用的信息。
常用的操作有集合SUM，TopN，Rank，Select操作。交互式分析一般要求实时响应。
集合（Set）
For a set of integers: S = {1, 2, 3, 1000}. Set operations:
tests: x ∈ S?
intersections: S1 ∩ S2
unions: S1 ∪ S2
differences: S1 ∖ S2
Jaccard Index (Tanimoto similarity) ∣S1 ∩ S2 ∣/∣S1 ∪ S2 ∣
有序集合（Ordered Set）
- Iterate:
in sorted order,
in reverse order,
skippable iterators (jump to first value ≥ x)
- Rank: how many elements of the set are smaller than k? (counting the number of ones up to a given position)
- Select: find the kth smallest value (finding the position of the k-th bit set)
- Min/max: find the maximal and minimal value
Broadword Implementation of Rank/Select Queries
研究论文：
- Vigna, Sebastiano. "Broadword implementation of rank/select queries." In International Workshop on Experimental and Efficient Algorithms, WEA 2008.
关联规则挖掘
关联规则挖掘（association rule mining），查找频繁项目集ItemSets。其中最有名的算法是Apriori算法。
基于位图的Apriori算法加速。
- Kim, Sung-Tan, Jae-Myung Kim, and Sang-Won Lee. "BAR: bitmap-based association rule: an implementation and its optimizations." In Proceedings of the 7th International Conference on Advances in Mobile Computing and Multimedia, pp. 627-631. ACM, 2009.
基数估计
基数估计（Cardinality Estimation），评估一个集合中不同数据项的个数的近似算法。比如，访问一个网站的独立IP个数。
- Flajolet, Philippe, Éric Fusy, Olivier Gandouet, and Frédéric Meunier. "Hyperloglog: the analysis of a near-optimal cardinality estimation algorithm." DMTCS Proceedings 1 (2008).
- Heule, Stefan, Marc Nunkesser, and Alexander Hall. "HyperLogLog in practice: algorithmic engineering of a state of the art cardinality estimation algorithm." In Proceedings of the 16th International Conference on Extending Database Technology, pp. 683-692. ACM, 2013.
