## All About Spherically Distributed Regression Errors

May 2, 2013
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(This article was first published on Econometrics Beat: Dave Giles' Blog, and kindly contributed to R-bloggers) This post is based on a handout that I use for one of my courses, and it relates to the usual linear regression model,                                  y = Xβ...

## Improved R Profiling Summaries

May 2, 2013
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In my last post I mentioned that I had improved on R’s `summaryRprof()` function with a custom function called `proftable()`. I’ve updated `proftable()` to take advantage of R 3.0.0’s ability to record line numbers while profiling. I’ve put it on github – you can get it there or below.

`proftable` reads in a file generated by...

## How R Grows

May 2, 2013
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by Joseph Rickert Saturday morning I was drinking my coffee wondering how much effort goes into R worldwide. (It’s my job.) I noticed that there were 4469 packages on CRAN, and it occurred to me that tabulating the packages by publication date would give some indication of how much effort is being expended to improve packags and keep them...

## Changing The Presidential Election with R in the Browser

May 2, 2013
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After I finished with the tutorial post d3 <- R with rCharts and slidify and then saw R creates d3/javascript charts in Ipython Style Notebook, a light clicked.  I could finally answer the lingering question I have had ever since I saw the NYT ...

## Concerto Simple Demonstration Test v4.b

May 2, 2013
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# This is my first attempt to post a example of a test using Concerto 4 beta.

# See Simple Test

# This is an extremely simple test.  Too simple to be useful to most people yet I believe it is didactically helpful.

The Following is the HTML code for Template 9. It is the form that the user first inputs...

## Do Torontonians Want a New Casino? Survey Analysis Part 1

May 2, 2013
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Toronto City Council is in the midst of a very lengthy process of considering whether or not to allow the OLG to build of a new casino in Toronto, and where.  The process started in November of 2012, and set … Continue reading

## Cut Dates Into Quarters

May 2, 2013
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Frequently I need to recode a date column to quarters. For example, at Excelsior College we have continuous enrollment so we report new enrollments per quarter. To complicate things a bit, our fiscal year starts in July so that July, August, and September represent the first quarter, January, February, and March are actually the third quarter. But sometimes...

## Writing from R to Excel with xlsx

May 1, 2013
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Paul Teetor, who is doing yeoman’s duty as one of the organizers of the Chicago R User Group (CRUG), asked recently if I would do a short presentation about a “favorite package”.  I picked xlsx, one of the many packages that provides a bridge between spreadsheets and R.  Here are the slides from my presentation

## NYT uses R to investigate NFL draft picks

May 1, 2013
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Last week, the New York Times published online an interactive tool to explore NFL draft picks, revealing the fact that there's not much relationship between an early pick and the star performers in the season: Kevin Quealy, graphics editor at the NYT, detailed the process behind creating this graphic on his chartsnthings blog. He and others on the graphics...

## R for dummies

May 1, 2013
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I already mentioned R for dummies a while ago on the ‘Og and never got around to read it from cover to back. Now that I am reduced to a dummy state with too much free time!, I can produce a full review of the book. R for dummies was written by two Belgian statistics

## R creates d3/javascript charts in Ipython Style Notebook

May 1, 2013
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I am not sure I have ever done a post like this, but I was so blown away I had to do this post simply to embed this amazing Youtube video from the author of the R packages rCharts and slidify.  Watch this screencast as he creates d3/raphael charts...

## When the “reorder” function just isn’t good enough…

May 1, 2013
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(This article was first published on Data and Analysis with R, at Work, and kindly contributed to R-bloggers) The reorder function, in R 3.0.0, is behaving strangely (or I’m really not understanding something).  Take the following simple data frame: df = data.frame(a1 = c(4,1,1,3,2,4,2), a2 = c(“h”,”j”,”j”,”e”,”c”,”h”,”c”)) I expect that if I call the reorder function on the a2...

## Book Review: The R Book, Second Edition (2013)

May 1, 2013
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The first edition of The R Book by Michael J. Crawley was an ambitious work, but managed to be slightly rubbish due to the atrocious typographical layout of the original book. The good news is that the new 2nd edition, released in 2013, has a substanti...

## A Crash Course in R

May 1, 2013
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This code has been kindly contributed by Robin Edwards

## A Command for Randomly Creating Sets of Elements from a Vector

May 1, 2013
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# This command pairs (of arbitrary length) together a list of items randomly.# I think it is useful for simulations matching individuals together.pairup = function(x, ncol=2, unmatched.self=T) {  # Calculate the length of the x vector.&n...

## A pathological glm() problem that doesn’t issue a warning

May 1, 2013
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I know I have already written a lot about technicalities in logistic regression (see for example: How robust is logistic regression? and Newton-Raphson can compute an average). But I just ran into a simple case where R‘s glm() implementation of logistic regression seems to fail without issuing a warning message. Yes the data is a

Related posts:

## New fixed.angle() Function

Hello morphometricians,
Below you can find a new fixed angle function addressing the problem discovered by Fabio Machado in the morphmet mail archive. We will include this function in our next schedule update to geomorph.

Cheers,

Erik

CODE:

...

## All you need is text – Markdown (via pandoc) for academia

May 1, 2013
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Many students struggle to find an adequte format for their thesis. Ironically the advent of “modern” WYSIWYG programms seems to make it harder to consistently format a text. While learning LaTeX may be a bit too much to ask for, markdown is a very minimal language that together with pandoc affords all typesetting needs for

## Volatility Regimes: Part 1

This is a ‘do over’ of a project I started while at my former employer in the fall of 2012. I presented part 1 of this
framework at the FX Invest West Coast conference on September 11, 2012. I have made some changes and expanded the
analysis since then. Part 2 is complete and will follow this post in the week...

## Le Monde puzzle [#818]

April 30, 2013
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The current puzzle is as follows: Define the symmetric of an integer as the integer obtained by inverting the order of its digits, eg 4321 is the symmetric of 1234. What are the numbers for which the square is equal to the symmetric of the square of the symmetric? I first consulted stackexchange to find

## Missing tikzDevice

April 30, 2013
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I love using tikzDevice. When preparing LaTeX documents I switched to prepare all graphs in GNU R and then port them to TeX using tikzDevice. Recently I have moved to GNU R 3.0.0 and was shocked to find that this package is no longer available on CRAN....

## What the BBC isn’t telling you

April 30, 2013
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Yesterday Gareth pointed me to this article on the BBC website. The underlying story has to do with Meredith Kercher's murder and the subsequent trial involving mainly her flat-mate Amanda Knox, in Perugia (Italy). As often in these grue...

## SAS Big Data Analytics Benchmark (Part One)

April 30, 2013
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by Thomas Dinsmore On April 26, SAS published on its website an undated Technical Paper entitled Big Data Analytics: Benchmarking SAS, R and Mahout. In the paper, the authors (Allison J. Ames, Ralph Abbey and Wayne Thompson) describe a recent project to compare model quality, product completeness and ease of use for two SAS products together with open source...

## Kalkalash! Pinpointing the Moments “The Simpsons” became less Cromulent

April 30, 2013
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Whenever somebody mentions “The Simpsons” it always stirs up feelings of nostalgia in me. The characters, uproarious gags, zingy one-liners, and edgy animation all contributed towards making, arguably, the greatest TV ever. However, it’s easy to forget that as a TV show “The Simpsons” is still ongoing—in its twenty-fourth season no less. For me, and

## Poor man’s integration – a simulated visualization approach

April 29, 2013
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$Poor man’s integration – a simulated visualization approach$

Every once in a while I encounter a problem that requires the use of calculus. This can be quite bothersome since my brain has refused over the years to retain any useful information related to calculus. Most of my formal training in the dark arts was completed in high school and has not been covered

## R 3.0.0 and Raring Ringtail (Ubuntu 13.04)

April 29, 2013
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New .deb packages for R 3.0.0 on Raring Ringtail (13.04) are available on both CRAN and my Launchpad PPA. Some notes for this release. The initial build for Raring Ringtail did not come with Tcl/Tk being supported. This issue has been addressed and...

## Feature Selection Strikes Back (Part 1)

April 29, 2013
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In the feature selection chapter, we describe several search procedures ("wrappers") that can be used to optimize the number of predictors. Some techniques were described in more detail than others. Although we do describe genetic algorithms and how they can be used for reducing the dimensions of the data, this is the first of series of blog posts that...

## A Brief Tour of the Trees and Forests

April 29, 2013
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Tree methods such as CART (classification and regression trees) can be used as alternatives to logistic regression. It is a way that can be used to show the probability of being in any hierarchical group. The following is a compilation of many of the key R packages that cover trees and forests.  The goal here