[R-pkgs] igraph 0.6 released

June 18, 2012
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Dear All, we have released version 0.6 of the igraph package today. This is a major new version, with a lot of new features, and (sadly) it is not completely compatible with code that was written for the previous igraph versions. (See “Major new features” below for details.) I have included below a list of (bigger) changes. Please see...

Tracking US Sentiments Over Time In Wikileaks

June 18, 2012
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Introduction I recently posted about using the Wikileaks cable corpus to find word use patterns, both over time, and in secret cables vs unclassified cables. I received a lot of good suggestions for further topics to pursue with the corpus, and probably the most interesting was the idea to do sentiment analysis over time on a variety of...

Tracking US Sentiments Over Time In Wikileaks

June 18, 2012
By

Introduction I recently posted about using the Wikileaks cable corpus to find word use patterns, both over time, and in secret cables vs unclassified cables. I received a lot of good suggestions for further topics to pursue with the corpus, and probably the most interesting was the idea to do sentiment analysis over time on a variety of...

Reproducible reports & research with knitr in R Studio

June 18, 2012
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Arguably, knitr (CRAN link) is the most outstanding R package of this year and its creator, Yihui Xie is the star of the useR! conference 2012. This is because the ease of use comparing to Sweave for making reproducible report. Integration of knitR and R Studio has made reproducible research much more convenience, intuitive and easier to

Example 9.35: Discrete randomization and formatted output

June 18, 2012
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A colleague asked for help with randomly choosing a kid within a family. This is for a trial in which families are recruited at well-child visits, but in each family only one of the children having a well-child visit that day can be in the study. The idea is that after recruiting the family, the research assistant...

Tracking US Sentiments Over Time In Wikileaks

June 18, 2012
By

Introduction I recently posted about using the Wikileaks cable corpus to find word use patterns, both over time, and in secret cables vs unclassified cables. I received a lot of good suggestions for further topics to pursue with the corpus, and probably the most interesting was the idea to do sentiment analysis over time on a variety of named entities. Sentiment analysis is the process...

R: Creating a shortcut to run a gWidgets GUI

June 18, 2012
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I’ve been playing around with using gWidgets on Windows over the last few weeks as a way of creating front ends for various functions and set of functions that I’ve created, so that non R users can have the benefit of these without having to write a single line of code. The likes of 4Dpiecharts … Continue reading...

Updates to package ‘intergraph’

June 18, 2012
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On June 17 a new version (0.6) of package ”igraph” was released. This new version abandoned the old way of indexing graph vertices with consecutive numbers starting from 0. The new version now numbers the vertices starting from 1, which is more consistent with the general R convention of indexing vectors, matrices, etc. Because this change is

Tracking US Sentiments Over Time In Wikileaks

June 18, 2012
By

Introduction I recently posted about using the Wikileaks cable corpus to find word use patterns, both over time, and in secret cables vs unclassified cables. I received a lot of good suggestions for further topics to pursue with the corpus, and probably the most interesting was the idea to do sentiment analysis over time on a variety of...

Cross sectional spread of stock returns

June 18, 2012
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A look at a simplistic measure of stock-picking opportunity. Motivation The interquartile range (the spread of the middle half of the data) has recently been added to the market portrait plots.  Putting those numbers into historical context was the original impulse. However, this led to thinking about change in stock-picking opportunity over time. Data Daily … Continue reading...

Comparing performance in R, foreach/doSNOW, SAS, and NumPY (MKL)

June 17, 2012
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This is a follow up to my previous post.  There is a quicker way to compute the function I created (basic cumulative sum) in R.Instead of:function f(x) {   sum = 0;   for (i in seq(1,x)) sum = sum + i   return(su...

List of Free Online R Tutorials

June 17, 2012
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According to the post on FREE online R tutorials from universities, I have received many email suggesting more and more tutorials. However some tutorials are not hosted in an academic institutes, so I decided to create this post to list such tutorials. If you know other tutorials, please kindly suggest me by email to [email protected]

Negros Quake Animation in R

June 17, 2012
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Taken from a previous post in other website, maps below show the locations of epicenters and sequence of earthquakes that struck Negros last February 6, 2012. The bottom image is the animation these maps using animation package in R. Data was taken fr...

Summary of community detection algorithms in igraph 0.6

June 17, 2012
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Based on Launchpad traffic and mailing list responses, Gabor and Tamas will soon be releasing igraph 0.6.  In celebration, I’ll be publishing a number of helpful lists and tables I’ve put together to organize information about igraph.   In…Read more ›

An exercise in R using local open data

June 17, 2012
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Last week I went to the “Government Open Data Hack Day” (godhd on twitter) in Birmingham (UK), organised by Gavin Broughton and James Catell. The idea was to get hold of local open data and try and make use of … Continue reading →

3D Maps in R

June 16, 2012
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Talking about elevation, one can also plot a wire frame 3D view of an area using the persp function. Using the same data source from my previous post, 3D view of Marinduque, Philippines was produced using the following code below: ################...

Why You Shouldn’t Conclude "No Effect" from Statistically Insignificant Slopes

June 16, 2012
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It is quite common in political science for researchers to run statistical models, find that a coefficient for a variable is not statistically significant, and then claim that the variable "has no effect." This is equivalent to proposing a research &#8...

integrating R with other systems

June 16, 2012
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I just returned from the useR! 2012 conference for developers and users of R. One of the common themes to many of the presentations was integration of R-based statistical systems with other systems, be they other programming languages, web systems, or enterprise data systems. Some highlights for me were an update to Rserve that includes

Euro2012 Viz: Second Group Games

June 16, 2012
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The second round of group games ended last night (sadly with Sweden’s elimination). Here is what the last number of days has done to the plots.

Name popularity

June 15, 2012
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This dynamic representation of the popularity of names over the years is a favorite. It’s not new, but I still find new things to appreciate, like names that used to apply to both sexes and now only one (Ellie), or vice versa (Harley). It seems l...

Carnon [and Core, end]

June 15, 2012
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Yet another full day working on Bayesian Core with Jean-Michel in Carnon… This morning, I ran along the canal for about an hour and at last saw some pink flamingos close enough to take pictures (if only to convince my daughter that there were flamingos in the area!). Then I worked full-time on the spatial

Cubism Horizon Charts in R

June 15, 2012
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Like many, I have been in awe of the d3.js and cubism.js visualization packages created by Mike Bostock. Mike Bostock @ Square talks about Time Series Visualization from Librato on Vimeo. The charts are beautiful and extraordinarily functional, so I th...

June 15, 2012
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From Wiki:"... the bottom and top of the box are always the 25th and 75th percentile (the lower and upper quartiles, respectively), and the band near the middle of the box is always the 50th percentile (the median). But th...

Project Euler — problem 10

June 15, 2012
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Just finish my last assignment for this week. IT’S WEEKEND, officially. Let me take a break to have a look at the tenth problem, another prime problem. It’s no doubt that prime is the center of the number theory and fundamental … Continue reading →

Using R in/for Governments

June 15, 2012
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Recently British government (by Office  of National Statistics: ONS) just published their version of R manual for analysis of the government survey. The links to PDF and MS word versions of the manual including the R syntax are as below. Note: The R syntax link is not working now. I am contacting the ONS, hope

How long does it take to get pregnant?

June 15, 2012
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My girlfriend’s biological clock is ticking, and so we’ve started trying to spawn. Since I’m impatient, that has naturally lead to questions like “how long will it take?”. If I were to believe everything on TV, the answer would be easy: have unprotected sex once and pregnancy is guaranteed. A more cynical me suggests that

Rounding in R

June 15, 2012
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Forgive me if you are already aware of this, but I found it quite alarming. I know that most code is interpreted by the computer in binary and we input in decimal, so problems can arise in conversion and with floating point. But the example I have below is so simple that it really surprised me.I was converting...

More on birthday probabilities

June 15, 2012
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Last week, Joe Rickert used R and four years of US Census data to create an image plot of the relative probabilities of being born on a given day of the year: Chris Mulligan also tackled this problem with R, but this time using 20 years of Census data from 1969 to 1988. Chris extracted the birthday frequencies using...

Standard, Robust, and Clustered Standard Errors Computed in R

June 15, 2012
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$Standard, Robust, and Clustered Standard Errors Computed in R$

Where do these come from? Since most statistical packages calculate these estimates automatically, it is not unreasonable to think that many researchers using applied econometrics are unfamiliar with the exact details of their computation. For the purposes of illustration, I am going to estimate different standard errors from a basic linear regression model: , using the