## Stata or R

February 10, 2011
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Recently I came across a complex model written in Access with complex SQL queries all over the place. The engineer who was maintaining it and I did some analysis and agreed that the model was using SQL in an unnatural way (things SQL isn't good at) - c...

## When will my papers appear as references (if they do…) ?

February 10, 2011
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Following my post on citations in academic journals, I wanted to go one step further in the understanding of the dynamic of citations. So here, the dataset looks like that: for each article, we have the name of the journal, the year of publicatio...

## Model weights for model choice

February 9, 2011
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$Model weights for model choice$

An ‘Og reader. Emmanuel Charpentier, sent me the following email about model choice: I read with great interest your critique of Peter Congdon’s 2006 paper (CSDA, 50(2):346-357) proposing a method of estimation of posterior model probabilities based on improper distributions for parameters not present in the model inder examination, as well as a more general

## Stationarity

February 9, 2011
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In time series work you often run into difficulties in modeling processes where the overall level of one variable (an input, for example) changes over time but the levels of another variable (an output) do not change. For instance if … Continue reading →

## New R User Groups in Europe

February 9, 2011
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It's great to see the growth in R user groups around the world, and now there are three new ones in western Europe: In Amsterdam, a new R user group has just formed, called amst-R-dam. They are just scheduling their first meeting now (vote here for a date) which will be in the next 3-4 weeks; In Geneva, the...

## Merci taxi!

February 9, 2011
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I am in Montpellier today for a general meeting of our EMILE ANR grant bi-yearly meeting, discussing ABC model choice and new applications of simulation methods in population genetics, including an upgrade of DIYABC into the 2.0 version. (The above is a picture comparing “true” Bayes factors with ABC versions, commented in my Zürich talk

## Troubling news for the teaching of evolution

February 9, 2011
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A recent survey reported in Science ("Defeating Creationism in the Courtroom, but not in the Classroom"),  suggests that high school teachers are not teaching evolution to the fullest extent, say, that grammar is being taught in the English c...

## Twos and Tens in Four Lines

February 9, 2011
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To chart the spread between 2-Year treasury yields and 10-Year treasury yields,  please type the simple code listed below into your R console. That is all, carry on as you were.require(quantmod)getSymbols(c("DGS10", "DGS2"), src="FRED")Ten_Two <...

## Using R for Introductory Statistics, Chapter 5, Probability Distributions

February 9, 2011
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In Chapter 5 of Using R for Introductory Statistics we get a brief introduction to probability and, as part of that, a few common probability distributions. Specifically, the normal, binomial, exponential and lognormal distributions make an appearance.For each distribution, R provides four functions whose names start with the letters d, p, q or r followed by...

## Using R for Introductory Statistics, Chapter 5, Probability Distributions

February 9, 2011
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In Chapter 5 of Using R for Introductory Statistics we get a brief introduction to probability and, as part of that, a few common probability distributions. Specifically, the normal, binomial, exponential and lognormal distributions make an appearance....

## Create a Web Crawler in R

February 8, 2011
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Admittedly I am not the best R coder, and I certainly have a lot to learn, but the code at the link below should provide you with an example of how easy it is to create a very (repeat: very) basic web crawler in R.  If you wanted to do this in SPSS, and I

## Opinions Not Backed by Money Are Not That Believable–Updated and with R

February 8, 2011
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As an update to http://timelyportfolio.blogspot.com/2010/12/opinions-not-backed-with-money-are-not.html, I have updated the revised data, added the past two months, and translated to R. If the world really is overly bullish on stocks as some suggest, I...

## Ubuntu – Installing R and RGedit Plugin

February 8, 2011
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R is a fantastic bit of software which I have been using on and off for a number of years since I gave up on SAS due to their (free for academics) annoying licenses and limited support for the things I wanted to do – R is infinitely flexible and totally free. Installing R on

## Utilizing multiple cores in R

February 8, 2011
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There are a couple of options in R, if you want to utilize multiple cores on your machine. These days my favorite is doMC package, which depends on foreach and multicore packages.in the section below squareroot for each number is calculated in parallel...

## Utilizing multiple cores in R

February 8, 2011
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There are a couple of options in R, if you want to utilize multiple cores on your machine. These days my favorite is doMC package, which depends on foreach and multicore packages.in the section below squareroot for each number is calculated in parallel...

## command line options in R: "optparse" package

February 8, 2011
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C/python style option parsing now available in R with "optparse" package. Check the documentation here and see below to see how it worksuser@node002 scripts \$ Rscript filter.transcripts.by.ncRNA.R -husage:  usage: filter.transcripts.by.ncRNA.R [op...

## command line options in R: "optparse" package

February 8, 2011
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C/python style option parsing now available in R with "optparse" package. Check the documentation here and see below to see how it worksuser@node002 scripts \$ Rscript filter.transcripts.by.ncRNA.R -husage:  usage: filter.transcripts.by.ncRNA.R [op...

## sqldf and grouping rows in R

February 8, 2011
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In R, you can treat tables (or data.frames as they are called in R) as SQL tables. That means you can query them as you would query a database with SQL commands. This is particularly useful 1) if you know SQL, hahah:)  2) if you have large tabl...

## sqldf and grouping rows in R

February 8, 2011
By

In R, you can treat tables (or data.frames as they are called in R) as SQL tables. That means you can query them as you would query a database with SQL commands. This is particularly useful 1) if you know SQL, hahah:)  2) if you have large tabl...

## Abstracts for R/Finance 2011 due February 15

February 8, 2011
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If you're planning to go to R/Finance 2011 in Chicago (and if you're doing quantitative finance with R, you definitely should), time is running out to submit your abstract for contributed talks. The best part of R/Finance is learning about all the interesting ways R is used to analyze financial data, so why not share your experiences as you...

## Revolution in the News

February 8, 2011
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Between the recent launch of Revolution R Enterprise 4.2 and the announcement of the SAS to R Challenge, there's been a flurry of recent news about Revolution Analytics and R in the media. Here's a quick recap: The Register's Timothy Prickett Morgan comments on the SAS to R Challenge: 'Red Hat for stats' goes toe-to-toe with SAS. "By supporting...

## Think academic journals look the same ? Well, some do…

February 8, 2011
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We have seen yesterday that finding an optimal strategy to publish is not that simple. And actually, it can be even more difficult in the case the journal rejects the paper (not because it is not correct, but because "it does not fit" with the stan...

## rjags 2.2.0 for Mac OS X

February 8, 2011
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Version 2.2.0 of the rjags package for R is now available on CRAN. Previously, the version of rjags for Mac (2.1.0) was incompatible with the latest release of the JAGS library (2.2.0).  Let me know if you have any further … Continue reading →

## 4 and a half myths about beta in finance

February 8, 2011
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Much of what has been said and thought about beta in finance is untrue. Myth 1: beta is about volatility This myth is pervasive. Beta is associated with the stock’s volatility but there is more involved.  Beta is the ratio of the volatility of the stock to the volatility of the market times the correlation … Continue reading...

## R courses from Statistics.com

February 7, 2011
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If you're looking for some in-depth training in R, here are some upcoming courses presented by R gurus and hosted by statistics.com to consider: Feb 11: Modeling in R (Sudha Purohit -- more details after the jump) Mar 4: Introduction to R - Data Handling (Paul Murrell) Apr 15: Programming in R (Hadley Wickham) Apr 29: Graphics in R...

## Example 8.24: MplusAutomation and Mplus

February 7, 2011
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In recent entries (here, here, and here), we've been fitting a series of latent class models using SAS and R. One of the most commonly used and powerful software package for latent class model estimation is Mplus. This commercial software includes su...

February 7, 2011
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February 7, 2011
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## Replicating the Body Fat Example from "Bayesian Model Averaging: A Tutorial" (1999) with BMS in R

February 7, 2011
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In their paper Bayesian Model Averaging: A Tutorial (Statistical Science 14(4), 1999, pp. 382-401), Hoeting, Madigan, Raftery and Volinsky (HMRV) do an exercise in Bayesian Model Averaging (BMA) at pp.394-397 in estimating body fat data from Johnson (...