Blog Archives

How do you say π^π^π?

September 15, 2014
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How do you say π^π^π?

Well, not that you really probably want to know how to say such an absurdly large number. However for those of you who are interested (allowing for rounding) it is:one quintillion, three hundred forty quadrillion, one hundred sixty-four trillion, one h...

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Fun with Bordered Cubes

September 9, 2014
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Fun with Bordered Cubes

I am interested in generating 3D reasoning items in R. To this end I have adapted some of the awesome functions built in the rgl library to my ends. My new function is 'cube' and it takes position and automatically sizes itself as a 1x1x1 cube though t...

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1.2 Millions Deaths by Ebola projected within Six Months?

September 5, 2014
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1.2 Millions Deaths by Ebola projected within Six Months?

The World Health Organization, Samaratins Purse, Doctors Without Borders, and other international medical emergency relief programs are desperately calling for additional resources in the international fight against Ebola that has already killed thousa...

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More Readable Code with Pipes in R

July 30, 2014
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More Readable Code with Pipes in R

Several blog posts have made mention of the 'magrittr' package which allows functional arguments to be passed to functions in a pipes style fashion (David Smith ).This stylistic option has several advantages:  1. Reduced requirements of nested par...

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Making random draws from an arbitrarily defined pdf

July 23, 2014
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Making random draws from an arbitrarily defined pdf

I recently found myself in need of a function to sample randomly from an arbitrarily defined probability density function. An excellent post by Quantitations shows how to accomplish this using some of Rs fairly sophisticated functional approximation to...

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The Rise and Fall of the name Jennifer

July 19, 2014
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The Rise and Fall of the name Jennifer

A recent fascinating post by Analysis at Large got me interested in naming trends analysis. The original post used Social Security data by state to map out the more frequent names by state. While this sounded interesting it turned out a single name (yo...

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RStudio Webinar with Hadley Wickham: The Grammar and Graphics of Data Science

July 17, 2014
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RStudio Webinar with Hadley Wickham: The Grammar and Graphics of Data Science

RStudio has recently announced a series of free webinars open to the public. The first of these seminars is given by Hadley Wickham, Rice University Professor, RStudio Chief Scientist, and general super-star of the R development world. Contributing aut...

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Item Response Theory and Item Information Exploration

July 10, 2014
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Item Response Theory and Item Information Exploration

In the following post I will map out some item information functions for item response theory (IRT) models using the common 3 parameter logistic model for binary responses. The model takes three parameters (obviously) which relate to the item features ...

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Estimating Required Coinage

July 5, 2014
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Estimating Required Coinage

I would like to code up a simple method of minimizing the number of coins required to give change.  Then I would like see what coins are most likely to be called into usage if change is required from a uniform draw between 1 cent and 499 cents. Exported from Notepad++ # Define denominations to search throughden...

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7 R Quirks That Will Drive You Nutty

May 5, 2014
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7 R Quirks That Will Drive You Nutty

7 R Quirks That Will Drive You Nutty StumpedEvery language has its idiosyncrasies. Some “designer”“ type languages have less due to extreme thoughtfulness of language engineers. I suspect Julia for example has many less quirks. However, despite...

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