payton数据之旅

摘要： Statistical approaches to randomised controlled trial analysisThe statistical approach used in the design and analysis of the vast majority of clinica... 阅读全文

摘要： Today is a good day to start parallelizing your code. I’ve been using the parallel package since its integration with R (v. 2.14.0) and its much easie... 阅读全文

摘要： From original post @http://analyticsblog.mecglobal.it/analytics-tools/bashr/In the world of data analysis, the term automation runs hand in hand with ... 阅读全文

摘要： dplyr 0.4.0January 9, 2015 inUncategorizedI’m very pleased to announce that dplyr 0.4.0 is now available from CRAN. Get the latest version by running:... 阅读全文

摘要： 关于分类算法我们之前也讨论过了KNN、决策树、naivebayes、SVM、ANN、logistic回归。关于这么多的分类算法，我们自然需要考虑谁的表现更加的优秀。 既然要对分类算法进行评价，那么我们自然得有评价依据。到目前为止，我们讨论分类的有效性都是基于分类成功率来说的，但是这个指标科学吗... 阅读全文

摘要： This post builds on aprevious post, but can be read and understood independently.As part of my course on statistical learning, we created 3D graphics ... 阅读全文

摘要： 1、余弦距离余弦距离，也称为余弦相似度，是用向量空间中两个向量夹角的余弦值作为衡量两个个体间差异的大小的度量。向量，是多维空间中有方向的线段，如果两个向量的方向一致，即夹角接近零，那么这两个向量就相近。而要确定两个向量方向是否一致，这就要用到余弦定理计算向量的夹角。余弦定理描述了三角形中任何一个夹角... 阅读全文

摘要： （1）C4.5算法的特点为：输入变量（自变量）：为分类型变量或连续型变量。输出变量（目标变量）：为分类型变量。连续变量处理：N等分离散化。树分枝类型：多分枝。分裂指标：信息增益比率gain ratio（分裂后的目标变量取值变异较小，纯度高）前剪枝：叶节点数是否小于某一阈值。后剪枝：使用置信度法和减少... 阅读全文

摘要： Joanna Zhao’s and Jenny Bryan’sR graph catalogis meant to be a complement to the physical book,Creating More Effective Graphs, but it’s a really nice ... 阅读全文

摘要： In preparation for a R Workgroup meeting, I started thinking about what would be my "Top 5 R Functions". I ruled out the functions for basic mechanics... 阅读全文