# Monthly Archives:May 2013

## Rmagic一个方便的连接python和r的接口

May 31,2013

Rmagic (http://ipython.org/ipython-doc/dev/config/extensions/rmagic.html) is the ipython extension that utilizes rpy2 in the back-end and provides a convenient interface accessing R from ipython.Compared with the generic use of rpy2,the rmagic extension allows users to exchange objects between ipython and R in a more flexible way and to run a single R function or a block

## How logistic regression work ?

May 31,2013

Discussing with a non statistician colleague,逻辑回归似乎不直观；一些基本问题，比如：-为什么不使用线性模型？-物流功能是什么？-我们如何手工计算，一步一步t…

## Generating Nice Looking Tree Diagrams in R

May 31,2013

This function generates nice looking tree diagrams (see sample) below from tree objects (generated by package tree).This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation,either version 3 of the License,或（由您选择）

May 31,2013

## 降雪

May 31,2013

Yesterday I had a short post reminding EViews users that their package (versions 7 or 8) will access all of the cores on a multi-core machine.在过去的几天里，我一直在我的台式机上玩R中的并行处理。It's something I've been meaning to do for a while,事实证明…

## The arteries of the world,在推特中

May 31,2013

What happens when you plot billions of geotagged Tweets on a map?你可以看到世界的动脉。这是欧洲：根据创造者米盖尔·里奥斯（工程经理，Data Visualization at Twitter),图表上的圆点代表了自2009年以来的每一条带地理标签的微博。颜色表示该地区的tweet数量，and the intensity shows where people...

## Are parallel computations worth it ?

May 31,2013

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Yesterday,丹尼尔·马塞利诺在他的博客上发表了一篇有趣的文章，untitled Parallel Processing: When does it worth?对于我目前正在写的一章，我也在问自己同样的问题。我很喜欢他的方法，so I tried,on my computer to do the same.I did use three packages to run parallel R codes,……

## Visualizing a One-Way ANOVA using D3.js

May 31,2013

A while ago I was playing around with the JavaScript package D3.js,and I began with this visualization—that I never really finished—of howa one-way ANOVA is calculated.I wanted to make the visualizationinteractive,我整合了一些互动元素。例如，if you hover over a data point it will show the residual,andits value will be highlighted in the...

## Regression regularization example

May 31,2013

Recently I needed a simple example showing when application of regularization in regression is worthwhile.Here is the code I came up with (along with basic application of parallelization of code execution).Assume you have 60 observations and 50 expla...

## accurate ABC: comments by Oliver Ratman [guest post]

May 31,2013

Here are comments by Olli following my post: I think we found a general means to obtain accurate ABC in the sense of matching the posterior mean or MAP exactly,and then minimising the KL distance between the true posterior and its ABC approximation subject to this condition.建筑工程的辅助概率