Monthly Archives: December 2012

ICERM Reproducibility Workshop: Day 1

December 10, 2012
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I'm attending a workshop on reproducibility at ICERM (Brown University) this week. I really appreciate this great opportunity offered by ICERM, Randy and Victoria. It is pretty exciting to meet people that you only knew before through indirect ways. O...

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Using (R) Markdown, Jekyll, & GitHub for a Website

December 10, 2012
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Introduction Markdown has been growing in popularity for writing documents on the web. With the introduction of R Markdown (see also Jeromy Anglim’s post on getting started with R Markdown) and knitr, R Markdown has simplified the publishing of R analysis on the web. I recently converted my website from Wordpress to Jekyll. Jekyll...

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A Simple Model for Realized Volatility

December 9, 2012
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A Simple Model for Realized Volatility

The post has two goals: (1) Explain how to forecast volatility using a simple Heterogeneous Auto-Regressive (HAR) model. (Corsi, 2002) (2) Check if higher moments like Skewness and Kurtosis add forecast value to this model. It will be a high … Continue reading →

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Handling missing data with Amelia

December 9, 2012
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Handling missing data with Amelia

So, what if you have data, but some of the observations are missing? Many statistical techniques assume no missingness, so we might want to “fill in” or rectangularize our data, by replacing missing observations with plausible substitutes....

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How to explore your heartbeat

December 8, 2012
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A few months ago, I bought a really cool book: Exploring Everyday Things (with R and Ruby). I learned many interesting and mostly useless things from the author, Sau Sheong Chang. Chapter 6 for example explains how to build a … Weiterlesen →

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Rcpp attributes: Even easier integration of GSL code into R

December 8, 2012
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Rcpp attributes: Even easier integration of GSL code into R

Following the Rcpp 0.10.0 release, I had written about simulating pi easily by using the wonderful new Rcpp Attributes feature. Now with Rcpp 0.10.1 released a good week ago, it is time to look at how Rcpp Attributes can help with external libraries. As this posts aims to show, it is a breeze! One key aspect is the use of...

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Evaluating term popularity with twitteR

December 8, 2012
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Evaluating term popularity with twitteR

I really wanted to put something together for this series on the twitteR package. Unfortunately, at the moment the number of interesting things than can be done with twitteR, as opposed to through API calls and RCurl, is limited. Regardless, I have Ye...

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Bridge hand distribution: simulation vs exact calculation

December 8, 2012
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Bridge hand distribution: simulation vs exact calculation

Recently I played bridge with my friends. Being frustrated with several consecutive poor hand distributions we asked ourselves a question what is the probability of having a hand good enough for a small slam. A well known rule of thumb is that you need...

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Fifty Shades of Grey in R

December 8, 2012
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Fifty Shades of Grey in R

My wife went out to her book group tonight and their book of the month was 50 Shades of Grey. Sadly, I could think of is that plotting 50 shades in R would be a neat exercise. require(ggplot2) grey50 <- data.frame( x = rep(1:10, 5), y = rep(1:5, ...

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XLLoop framework

December 7, 2012
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XLLoop framework

Today I want to highlight the XLLoop framework : Excel User-Define Functions in in any language. The XLLoop consists of two main components: An Excel addin implementation (XLL written in c++). A server and framework written in R (or/and in many other languages). The XLLoop allows you to connect Excel and R in very simple

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