Tips for Making R User Group Videos

September 17, 2012
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Tips for Making R User Group Videos

Today's guest post is from Ron Fredericks, videographer and co-founder of LectureMaker, LLC — ed. I was initially surprised to find R user groups (RUGs) so popular. I filmed my first R session during the 2009 Predictive Analytics World in San Francisco. I filmed several more R user sessions over the past three years along with business/science clients and...

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What is Tony talking about?

September 17, 2012
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What is Tony talking about?

I first experimented with word clouds several years ago and used them to visualise the speeches of Kevin Rudd and Malcolm Turnbull. I have now learned from the Fell Stats blog (via R-Bloggers) that there is an R package for generating word clouds.  The package makes use of tm, a text mining package for R, which I have been

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Olimpic predictions – from an R web service provider’s point of view

September 17, 2012
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Olimpic predictions – from an R web service provider’s point of view

Hello, world!Back in July we have read Markus Gesmann’s great blogpost about a prediction for the 100m final in London. Soon we decided to create similar estimates about the forthcoming events and started to post our results on Facebook.We would like to emphasise again that these kind of extrapolated estimates are rather just for fun and we also think...

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Variability of garch estimates

September 17, 2012
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Variability of garch estimates

Not exactly pin-point accuracy. Previously Two related posts are: A practical introduction to garch modeling garch and long tails Experiment 1000 simulated return series were generated.  The garch(1,1) parameters were alpha=.07, beta=.925, omega=.01.  The asymptotic variance for this model is 2.  The half-life is about 138 days. The simulated series used a Student’s t distribution … Continue reading...

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Create Beamer/knitr Lecture Slideshow with Bash, Explain the Script with knitr

September 17, 2012
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Setting up a beamer slideshow is tedious. Creating new slideshows with the same header/footer/style files every week for your course lectures is very very tedious. To solve this problem I created a simple bash shell script. When you run the script in...

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Scholarly metadata from R

September 17, 2012
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Metadata! Metadata is very cool. It's super hot right now - everybody is talking about it. Okay, maybe not everyone, but it's an important part of archiving scholarly work. We are working on a repo on GitHub rmetadata to be a one stop shop for quer...

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Online Questionnaire & Report Generation with Google Drive & R

September 17, 2012
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Here's how I did it in 3 easy steps: (1) Set up a form in Google Docs/Drive. (2) Choose "Actions" and "Embed in Website" to get the URL for the iframe and put it in a post, like below. Then, go to the spreadsheet view of the form on Google Docs/Drive a...

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Etymology

September 16, 2012
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Chris and I started this blog as an outlet for the work we were already doing every day: writing code and trying to avoid forgetting how we wrote it. To that end, gist.github.com is an extremely useful resource, and this blog allows us to add a little ...

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Changes in optimization performance of gcc over time

September 16, 2012
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Changes in optimization performance of gcc over time

The SPEC benchmarks came out a year after the first release of gcc (in fact gcc was and still is one of the programs included in the benchmark). Compiling the SPEC programs using the gcc option -O2 (sometimes -O3) has always been the way to measure gcc performance, but after 25 years does this way

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The R-Podcast Episode 10: Adventures in Data Munging Part 2

September 16, 2012
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I’m happy to present episode 10 of the R-Podcast! Season 1 of the R-Podcast concludes with part 2 of my series on data munging, in which I discuss issues surrounding importing data sets contained in HTML tables. I share how I used the XML and RCurl packages to validate and import data from hockey-reference.com for

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What’s the smallest amount you can’t make with 5 coins ?

September 16, 2012
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What’s the smallest amount you can’t make with 5 coins ?

My amazing, awesome wife often comes up with the little puzzles for our amazing children, and this one seemed destined to be solved in R. So, using up to 5 coins (1p, 2p, 5p, 10p, 20p and 50p) first she asked our kids whether they could make every val...

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New version of devtools: 0.8

September 16, 2012
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New version of devtools: 0.8

We’re pleased to announce a new version of devtools, the package that makes R package development easy. The main features in this version are: A complete rewrite of the code loading system which simulates namespace loading much more accurately – this means using load_all is much closer to installing and loading the package. It also

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Confidence Regions for Regression Coefficients

September 16, 2012
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Confidence Regions for Regression Coefficients

Let’s consider the usual linear regression model, with the full set of assumptions:                     y = Xβ + ε ;    ε ~ N , (1)where X is a non-random (n × k) matrix with full column rank.Recall that, under our usual set of assumptions...

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Confidence Regions for Regression Coefficients

September 16, 2012
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Confidence Regions for Regression Coefficients

Let’s consider the usual linear regression model, with the full set of assumptions:                     y = Xβ + ε ;    ε ~ N , (1)where X is a non-random (n × k) mat...

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Football model

September 16, 2012
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Football model

After reading Dutch football data (Eeredivisie 2011-2012) and making a predictions display it is time to look at a few simple models to predict goals. To reiterate the data setup, each game played consists of two rows in the data frame. ...

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World Cup 2006 First Goal R Analysis

September 16, 2012
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Quite a while ago my amazing wife asked me if it was possible to find the time of the first goal for the 2006 FIFA World Cup matches.  I was using R at the time and thought it was possible.  Here are the scripts I wrote to scrape the info fro...

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California High School Graduation and Dropout Rates

September 16, 2012
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California High School Graduation and Dropout Rates

Abstract The California Deparment of Education recently (June 2012) had a news release on the increase in high school (grades 9-12) graduation rates and decrease in dropout rates. The data used by the Department was from two cohorts (4-year periods) o...

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project-euler–problem 65

September 16, 2012
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The square root of 2 can be written as an infinite continued fraction. \( \sqrt{2} = 1+\frac{1}{2+\frac{1}{2+\frac{1}{2+\frac{1}{2+?}}}} \) \sqrt{2} = 1+\frac{1}{2+\frac{1}{2+\frac{1}{2+\frac{1}{2+?}}}} The infinite continued fraction can be written, √2 = , (2) indicates that 2 repeats ad infinitum. In a similar way, √23 = . Read More: 1030 Words Totally

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Download your Facebook photos using R

September 15, 2012
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Download your Facebook photos using R

So tonight I wanted to download all my Facebook pictures. For some reason the zip file was corrupted each of the 3 times I downloaded, so I remembered that some time ago I was playing around with an R project named Facebook Data-Mining. The project is conveniently located at github and you can access it here. Looking

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Download your Facebook photos using R

September 15, 2012
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Download your Facebook photos using R

So tonight I wanted to download all my Facebook pictures. For some reason the zip file was corrupted each of the 3 times I downloaded, so I remembered that some time ago I was playing around with an R project named Facebook Data-Mining. The project is conveniently located at github and you can access it here. Looking ...read more

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Preferential attachment for network

September 15, 2012
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I am currently taking the networked life course on Coursera.org offered by Professor Michael Kearns from the University of Pennsylvania.  I have been took several courses including machine learning, natural language processing since the platf...

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N-Way ANOVA

September 15, 2012
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N-Way ANOVA example Two-way analysis of variance is where the rubber hits the road, so to speak. This extends the concepts of ANOVA with only one factor to two factors. When there are two factors this means that there can be an interaction between the two factors that should be tested. As one might expect

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An implementation of the Newton-Raphson algorithm in C/C++ and R

September 14, 2012
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An implementation of the Newton-Raphson algorithm in C/C++ and R

Today, we write a small piece of C/C++ code that implements the well-known Newton-Raphson algorithm (see, Mathworld). We also provide the R code. Exercise: Find the unique root of the function  using the Newton-Raphson method. Notice that we choose a function … Continue reading →

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Slightly-more-than-basic sentiment analysis

September 14, 2012
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I became interested in sentiment analysis a few months ago as a matter of pure practicality. The company I work for does a lot of customer-satisfaction surveys. Respondents rate various aspects of our products, but they also have the opportunity to answer a bunch of open-ended questions in their own voices. That kind of information

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Getting into R, RCommander, JGR and Deducer

September 14, 2012
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I've been meaning to post something about R for a while, but never got started, and now have a pile of things I'd like to post, so it's time to get started. I first started using R during my Master Dissertation where I had to do some stats.  I've ...

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Visualize complex data with subplots

September 14, 2012
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Visualize complex data with subplots

Today's guest post comes from Garrett Grolemund, a software developer at RStudio — ed. I think of graphs as a type of visual summary for data. Yet I rarely see graphs used this way within visualizations. Consider tile plots. They group data into 2d bins and then summarize each group with a number. This approach is a go-to tool...

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Simulation metamodeling with constraints

September 14, 2012
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Simulation metamodeling with constraints

Last week I have posted about using simulation metamodeling to verify results of analytical solution of the model. After posting it I realized that the solution presented there can be improved by using knowledge of simulation model struc...

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Mapping Bike Accidents in R

September 14, 2012
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Mapping Bike Accidents in R

At last weekend’s Hack Ta Ville event here in Montreal, I joined up with some talented urban planners and web devs to realize Vélobstacles. The idea of the project is to crowd source information on cycling conditions around the city. As with any crowd sourcing project, we were faced with the problem of seeding the

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Great Circles, Black Holes, and Community Events Part 3 of 3

September 14, 2012
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Great Circles, Black Holes, and Community Events Part 3 of 3

The second community event is the Soldier Hollow Junior Olympics (SoHo), again found in the Heber Valley area. Building upon the previous posts (part 1 and part 2) this one will show an event that has more people coming from greater distance. Take the bar charts for the number of participants and the cities they are...

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