Monthly Archives: January 2013

Demonstrate your R code with an interactive, embeddable Javascript widget

January 6, 2013
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Demonstrate your R code with an interactive, embeddable Javascript widget

Let visitors execute and play with simple R examples right on your web page, thanks to a web service and an embeddable widget provided by the Sage project.

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2012 Summary and 2013 Plans

January 6, 2013
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2012 Summary and 2013 Plans

2012 was a very important year for me. It was my first full year of trading only pure quantitative strategies. It was a very successful year as well, despite the fact that the S&P 500 returned 16% (including dividends) – a tough to beat benchmark. The strategy I use on the SPY, for which I

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Bayesian Classification with Gaussian Process

January 6, 2013
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Bayesian Classification with Gaussian Process

Despite prowess of the support vector machine, it is not specifically designed to extract features relevant to the prediction. For example, in network intrusion detection, we need to learn relevant network statistics for the network defense. In consu...

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More Principal Components Fun

January 6, 2013
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More Principal Components Fun

Today, I want to continue with the Principal Components theme and show how the Principal Component Analysis can be used to build portfolios that are not correlated to the market. Most of the content for this post is based on the excellent article, “Using PCA for spread trading” by Jev Kuznetsov. Let’s start by loading

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PLS Path Modeling with R: A Comprehensive Tutorial by Gaston Sanchez

January 6, 2013
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PLS Path Modeling with R: A Comprehensive Tutorial by Gaston Sanchez

Gaston Sanchez has just published an online pdf of his new book PLS Path Modeling with R.I have been using Gaston's plspm r package for a couple of years to analyze marketing data.  I started when I needed to test a path model in wh...

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Querying an SQLite database from R

January 6, 2013
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You have an SQLite database, perhaps as part of some replication materials, and you want to query it from R. You might want to be able to say: results <- runsql("select * from mytable order by date") and get the results back as an R object. Here's a function to do it. In the following,

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What Are Your Favorite Methodology and Statistics Blogs?

January 6, 2013
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I recently searched for a list of the "top statistics blogs" or the "top methodology blogs" and I couldn't find a recent compilation. This contrasts with visualization blogs, which are relatively easily to find (e.g. top visualization blogs). I've decided to initiate the provision of this public good, but would like to draw on others'

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source_GitHubData: a simple function for downloading data from GitHub into R

January 6, 2013
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Update 31 January: I've folded source_GitHubData into the repmis packaged. See this post. Update 7 January 2012: I updated the internal workings of source_GitHubData so that it now relies on httr rather than RCurl. Also it is more directly descended ...

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Sequential testing in a triangle test setting

January 6, 2013
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It is well known the binomial test never has an error of exactly 5%. You aim for at most 5%, calculate the number correct to get there and end up with an error of e.g 2%. This is a shame but there is no solution. However, it is also an opportunity; the...

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tolower() – error catching unmappable characters

January 6, 2013
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tolower() – error catching unmappable characters

The tolower() function returns an error where it can’t map to the Unicode character set of the input data – a common occurrence when analysing social media data with emoticons. Emoticons are those symbols that are commonly used on mobile phones but aren’t always recognised on all platforms. For example, when converting tweets to @delta

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