A recent working paper has come out arguing for the existence of Hot Hands (in basketball), a concept psychologists had dismissed decades ago. Hot hands is where a player is thought to have a higher likelihood of scoring the next basket if the last three baskets where shot successfully. (In ... [Read more...]

Test your skills with this R-powered R assessment of base R knowledge! Built using the R powered adaptive testing platform Concerto, this assessment provides a short but powerful tool at evaluating your base R understanding relative to that of your pe... [Read more...]

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Make your own hotly criticized circle graph! The recent critical post on R-bloggers has got me wanting to make my own bubble graphs despite the popular criticism of the graph. After some attempts I have produced something that looks similar but needs s... [Read more...]

Taking the very 'waterfall graph' code posted by Robert Grant I have added some features (resistance Overall I find the graphs produced from this code to be beautiful and fascinating though I am not sure if I would really use them as a form of data exp... [Read more...]

I feel like a sculptor who has been using the same metal tools for the last four years and happened to have looked at my comrades and found them sporting new, sleek electric tools. Suddenly all of the hard work put into maintaining and adapting my meta... [Read more...]

A month ago when the WHO was projecting estimates of the effect of current outbreak of Ebola being as deadly as affecting 20,000 people, I ran some elementary modelling and found that these estimates are far too small given the current trend.  The... [Read more...]

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... [Read more...]

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... [Read more...]

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... [Read more...]

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... [Read more...]

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... [Read more...]

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... [Read more...]

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... [Read more...]

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 ... [Read more...]

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 ... [Read more...]

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 its quirkiness R has become an amazingly flexible resource for a diverse range of ... [Read more...]

Programming New Things I currently have been programming in R for more than half a decade and can now fondly look back on the days when I went on a spring break with Venables' little blue book (now out of print).  Back then I was entertained and wowed by R’... [Read more...]

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