数据挖掘概念与技术 CHAPTER2-了解数据.ppt

分布度量/代数度量/整体度量 从数据挖掘角度，需要考察如何在大型数据可中有效计算度量。 分布式度量 distributive measure 可通过如下方法计算的度量（函数）：将数据划分成较小子集，计算每个子集的度量，合并计算结果得到整个数据集的度量值。 Sum, count 代数度量 algebraic measure 可用一个函数于一个或多个分布度量计算的度量 整体度量 holistic measure 必须对整个数据集计算的度量 散布图的例子 像素图的例子 * 09/09/25MK: New example (previous one was from Tan’s book). Chapter 3: Statistics Methods Co-variance distance K-L divergence * 08/10/23: This slide was out of date. Draft of new version above. Cut out the following: Data description, data exploration, and measure data similarity set the basis for quality data preprocessing A lot of methods have been developed but data preprocessing still an active area of research * MK 08.11.02: This needs to be updated to reflect changes. * * * CC (conference call) 08.11.02: Need to check Wiki to update references. * CC 08/11/02: Need a good survey. JH or JP may find a good book on amazon in order to update this slide. JH’s colleagues may generate some images for book. We may consider the following books. Visualizing Data: Exploring and Explaining Data with the Processing Environment - Paperback - Illustrated (Jan 11, 2008) by Ben Fry. JH: I have ordered the book. * /companions/1558606890/pictures/Chapter_01/fig1-6b.gif * * * * * * * “two attributes mapped to axes, remaining attributes mapped to angle or length of limbs”. Look at texture pattern. * MK 08/10/18: Is it “Treemap” or “Tree-Map”? - inconsistent in this file. * * * * Picture: /hcil/treemap-history/all102001.jpg * * JH: I have not found a good infocube picture on the web * /articles/visualization * Keep here because keeping it in clustering chapter seems far away. 08.11.02 * Distance is just once way of measuring dissimilarity (wiki). Changed “register only the distance” to “registers only the difference” or “dissimiarity”? * * MK: I tried to change equations so as to match notation in book, but each time I try to install the equation editor, it fails! Agh! * * MK: For lecture, this may be OK here, but I think discussion of