# Monthly Archives: August 2013

August 26, 2013
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Yesterday evening, I wanted to play with Twitter, and see which websites I was using as references in my tweets, to get a Top 4 list. The first problem I got was because installing twitteR on Ubuntu is not that simple ! You have to install properly RCurl… But you before install the package in R, it is necessary...

## Revolution Analytics: Top Innovator for Data Visualization

August 26, 2013
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We're proud that Revolution R Enterprise recently received the award for Top Innovator for Data Visualization from DataWeek. The R language has long been at the forefront of data visualization, and is the graphical engine behind many of the unique data visualizations you often see on the web and in print, including in the New York Times, at FlowingData...

## MCMSki IV, Jan. 6-8, 2014, Chamonix (news #7)

August 26, 2013
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More exciting (and important!) news about MCMSki IV: First, some if not all of the 9 invited and the 16 contributed sessions are about now documented by abstracts. The program is completely set! If you plan to present a poster, remember to send me by email (a) surname, name (institution): title as the subject, (b)

## Using R to visualize Karpov-vs-Kasparov Lifetime winner-take-all tally

August 26, 2013
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The Karpov vs. Kasparov rivalry holds a special place in the chess world.The idea behind this analysis is simple. If we take their lifetime games, plot the wins, what would it look like? We introduce one twist -- we'll be plotting the "winner-take-all"...

## Latent Variable Mixture Modeling: When Heterogeneity Requires Both Categories and Dimensions

August 26, 2013
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Dichotomies come easily to us, especially when they are caricatures as shown in this cartoon.  These personality types do seem real, and without much difficulty, we can anticipate how they might react in different situations.  For example, if...

## R vs Python: Practical Data Analysis (Nonlinear Regression)

August 26, 2013
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I’ve written a few previous posts comparing R to Python in terms of symbolic math, optimization, and bootstrapping. All of these posts were pretty popular. The last one especially. Many of the commenters brought up the fact that R, while … Continue reading →

## predictNLS (Part 2, Taylor approximation): confidence intervals for ‘nls’ models

August 26, 2013
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$predictNLS (Part 2, Taylor approximation): confidence intervals for ‘nls’ models$

Initial Remark: Reload this page if formulas don’t display well! As promised, here is the second part on how to obtain confidence intervals for fitted values obtained from nonlinear regression via nls or nlsLM (package ‘minpack.lm’). I covered a Monte Carlo approach in http://rmazing.wordpress.com/2013/08/14/predictnls-part-1-monte-carlo-simulation-confidence-intervals-for-nls-models/, but here we will take a different approach: First- and second-order

## Changeability of Value at Risk estimators

August 26, 2013
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How does Value at Risk change through time for the same portfolio? Previously There has been a number of posts on Value at Risk, including a basic introduction to Value at Risk and Expected Shortfall. The components garch model was also described. Issue The historical method for Value at Risk is by far the most commonly … Continue reading...

## Using JavaScript visualization libraries with R

August 26, 2013
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This is a short tutorial on knitr/markdown and JS visualization packages googleVis and rCharts. With these packages you can create web pages with interactive visualizations just using R. This will require minimal or no knowledge of HTML ...