## Update: Extending Commodity time series

July 3, 2013
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I showed an example of Extending Commodity time series back in 2012. Since then, the web site that I used to get the Thomson Reuters/Jefferies CRB Index data is no longer working. But there are a few alternatives: Thomson Reuters / Jefferies CRB Index. To get data, first select “TRJ/CRB Index-Total Return”, next click “See

## Using R and Integer Programming to find solutions to FlowFree game boards

July 3, 2013
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Using R and Integer Programming to find solutions to FlowFree game boards What is FlowFree?A popular game (iOS/Android) on a square board with simple rules. As the website states: Connect matching colors with pipes to create a flow. Pair all color...

## Facts and fallacies of the AIC

July 3, 2013
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Akaike’s Information Criterion (AIC) is a very useful model selection tool, but it is not as well understood as it should be. I frequently read papers, or hear talks, which demonstrate misunderstandings or misuse of this important tool. The following points should clarify some aspects of the AIC, and hopefully reduce its misuse. The AIC is a penalized likelihood,...

## Plan B

July 3, 2013
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Thank goodness, I think that even if this statistician business turns out badly, I can still make a living with rafting (if only by begging for money, in exchange for looking ridiculous in the swim suit)... As part as my brother's stag do, we went...

## Fun with random effects in loss reserving

July 3, 2013
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For some time now, I’ve advocated for the view that non-life loss reserving constitutes a categorized linear regression. I’ll emphasize that the idea of a linear regression isn’t remotely novel. Further, the categorization is the de facto approach. I’m merely recognizing it and suggesting instances where a decision may be made about the optimality of

## The R journal – Volume 5/1, June 2013

July 3, 2013
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The new R Journal is out! Click for a complete table of content with links to all papers.

## The hat trick

July 3, 2013
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In his book Quantum Computing Since Democritus, Scott Aaronson poses the following question: Suppose that you’re at a party where every guest is given a hat as they walk in. Each hat has either a pineapple or a watermelon on top, picked at random with equal probability. The guests don’t get to see the fruit

## In case you missed it: June 2013 Roundup

July 3, 2013
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In case you missed them, here are some articles from June of particular interest to R users: You can create a Word document from a template and an R script with the R2DOCX package. Joe Rickert reviews books and other resources for learning about time series analysis in R. Timely Portfolio covers 15 years of history of time series...

July 3, 2013
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Get your fresh copy of the R-Journal from here.

## Predictive analysis on Web Analytics tool data

July 3, 2013
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In our previous webinar, we discussed on predictive analytics and basic things to perform predictive analysis. We also discussed on an eCommerce problem and how it can be solved using predictive analysis. In this post, I will explain R script that I used to perform predictive analysis during webinar. Before I explain about R script,

## Fixing R’s NAMED problems in pqR

July 2, 2013
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In R, objects of most types are supposed to be treated as “values”, that do not change when other objects change. For instance, after doing the following: a <- c(1,2,3) b <- a a <- 0 b is supposed to have the value 2, not 0. Similarly, a vector passed as an argument to a

## Which airline should you be loyal to?

July 2, 2013
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LOYALTY PROGRAM CHOICE BASED ON DEPARTURE COUNT If you read Decision Science News, you’re probably a professor or grad student or researcher or policy type who flies around a lot to conferences, symposia, workshops, tutorials, summer schools, and all-hands meetings. You travel the globe to give talks and work with co-authors. All this flying around The post Which...

## The Mechanics of Data Visualization

July 2, 2013
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I recently presented about the mechanics of data visualization at the CLaRI Literacy Conference to a group of researchers, teachers and school administrators. The presentation is based on the work of Few (2012; 2009). While the presentation itself is not about … Continue reading →

## Le Monde puzzle [#827]

July 2, 2013
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Back to R (!) for the current Le Monde puzzle: Given an unknown permutation of the set {1,…,6}, written on the faces of a cube, there exist a sequence of summits such that increasing by one unit the three numbers of the faces sharing the successive summits in the sequence leads to identical values over

## Scaling the R ecosystem: Possible Directions for Improving Dependency Versioning

July 2, 2013
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A paper published today in The R Journal discusses a fundamental limitation affecting reliability and reproducibility of R code. It explains how lack of dependency versioning causes R based applications break down, Sweave documents to stop working and CRAN to hit scaling problems. The paper suggests several solutions inspired by other open-source communities that could ...

## A Brief Look at Mixture Discriminant Analysis

July 2, 2013
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Lately, I have been working with finite mixture models for my postdoctoral work on data-driven automated gating. Given that I had barely scratched the surface with mixture models in the classroom, I am becoming increasingly comfortable with them. With this in mind, I wanted to explore their application to classification because there are times when a single class is clearly made up of...

## Parse arguments of an R script

July 2, 2013
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R can be used also as a scripting tool. We just need to add shebang in the first line of a file (script):#!/usr/bin/Rscriptand then the R code should follow.Often we want to pass arguments to such a script, which can be collected in the script by the c...

## Access individual elements of a row while using the apply function on your dataframe (or “applying down while thinking across”)

July 2, 2013
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The apply function in R is a huge work-horse for me across many projects.  My usage of it is pretty stereotypical.  Usually, I use it to make aggregations of a targeted group of columns for every row in a dataframe. … Continue reading →

July 2, 2013
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Like your .bashrc, .vimrc, or many other dotfiles you may have in your home directory, your .Rprofile is sourced every time you start an R session. On Mac and Linux, this file is usually located in ~/.Rprofile. On Windows it's buried somewhere in the R...

## There is definitely R in July

July 1, 2013
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The useR!2013 conference in Albacete, Spain, will commence next Wednesday, 10 July, and on the day before Diego and I will give a googleVis tutorial. The following Monday, 15 July, the first R in Insurance event will take place at Cass Business School ...

## Some Common Approaches for Analyzing Likert Scales and Other Categorical Data

July 1, 2013
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$Some Common Approaches for Analyzing Likert Scales and Other Categorical Data$

Analyzing Likert scale responses really comes down to what you want to accomplish (e.g. Are you trying to provide a formal report with probabilities or are you trying to simply understand the data better). Sometimes a couple of graphs are sufficient and a formalize statistical test isn’t even necessary. However, with how easy it is

## integral priors for binomial regression

July 1, 2013
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Diego Salmerón and Juan Antonio Cano from Murcia, Spain (check the movie linked to the above photograph!), kindly included me in their recent integral prior paper, even though I mainly provided (constructive) criticism. The paper has just been arXived. A few years ago (2008 to be precise), we wrote together an integral prior paper, published

## Using ESS-Remote

July 1, 2013
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If you use R and ssh into other machines a lot, e.g. for doing some big data stuff on ec2, ess-remote is a great tool. Just use M-x ssh to ssh into the remote machine, then launch R. Now just M-x ess-remote and you can use the R process just like a local process! Productivity win. Also see

## Maximum Entropy Bootstrap Rescale and Symmetrize

July 1, 2013
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R code for changing scale without changing mean or to make a probability distribution symmetric. These are commonly encountered problems by R programmers. We provide code for both of these tasks in the context of maximum entropy bootstrap (meboot) package in R.

## OpenAnalytics @ UseR 2013: What’s on the Program?

July 1, 2013
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Monday 1 July 2013 - 22:37 OpenAnalytics is once more proud sponsor of the yearly R User Conference and sent a strong delegation to present some of its recent work. On Tuesday July 9 Tobias Verbeke and Stephan Wahlbrink give a pre-conference...

## OpenAnalytics @ UseR 2013: What’s on the Program?

July 1, 2013
By

Monday 1 July 2013 - 22:37 OpenAnalytics is once more proud sponsor of the yearly R User Conference and sent a strong delegation to present some of its recent work. On Tuesday July 9 Tobias Verbeke and Stephan Wahlbrink give a pre-conference...

## Power and sample size calculator for mitochondrial DNA association studies (Shiny)

July 1, 2013
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The functions detailed inside the piece of code below (in a Gist) has been useful for me when I had to calculate many possible scenarios of statistical power and sample size. The formulae were taken from the article of Samuels … Sigue leyendo →

## Web Analytics Visualization through ggplot2

July 1, 2013
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During our last webinar, we covered some of the basic ideas behind ggplot2, the R Visualization package by Dr. Hadley Wickham. In this blog post I will walk through the example that I covered during the webinar. In order to carry out the examples yourself, you may download the dummy datasets from this link Creating

## R and PostgreSQL – using RPostgreSQL and sqldf

July 1, 2013
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PostgreSQL and R can often be used together for data analysis - PostgreSQL as database engine and R as statistical tool. In this article you will learn how to access data stored in PostgreSQL database and how to write the data back using RPostgreSQL an...