# Monthly Archives: July 2014

## Women Graduates in Math, Statistics, and Computer Information Systems

July 3, 2014
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One of the more interesting talks at this year’s useR! Conference was the heR Panel discussing the role of women in the R community. They estimate that fewer than 15% of package authors are women. One of the points brought up was that this is less than the percentage of women in statistics. Perhaps this is more...

## Efficient Ragged Arrays in R and Rcpp

July 3, 2014
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When is R Slow, and Why? Computational speed is a common complaint lodged against R. Some recent posts on r-bloggers.com have compared the speed of R with some other programming languages , and showed the favorable impact of the new compiler package on run-times . I and others have written about using Rcpp to easily write C++...

## useR! 2014 Highlights

July 3, 2014
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My talk went well; here are the slides and a link to the paper pre-print. Hadley Wickham gave an excellent tutorial on dplyr. Based on the talk I saw, I think I will take the data sets from the book and make some public visualizations on the Plotly we...

## Currency Exchange Rate Forecasting with ARIMA and STL

July 3, 2014
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I have made an example of time series forecasting with R, demonstrating currency exchange rate forecasting with the ARIMA and STL models. The example is easy to understand and follow. R source files are provided to run the example. The … Continue reading →

## How to Remember the Poisson Distribution

July 3, 2014
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The Poisson cumulative distribution function (CDF) $$F(α,n) = \sum_{k=0}^n \dfrac{α^k}{k!} \; e^{-α} \label{eqn:pcdf}$$ is the probability of at most $n$ events occurring when the average number of events is α, i.e., $\Pr(X \le n)$. Since \eqref{eqn:pcdf} is a probability function, it cannot have a value greater than 1. In R, the CDF is given by the...

## Beer and Pie | rCharts pie charts with d3pie

July 3, 2014
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In honor of the 4th of July, I thought a quick example of a pie chart on beer using the wonderful new d3pie library would be appropriate.  The rCharts binding with d3pie is simply an experiment now, but expect more in the near future.   Using slidify...

## UseR! 2014 Tutorials

July 3, 2014
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by Joseph Rickert UserR! 2014 got under way this past Monday with a very impressive array of tutorials delivered on the day that the conferences organizers were struggling to cope with a record breaking crowd. My guess is that conference attendance is somewhere in the 700 range. Moreover, this the first year that I can remember that tutorials were...

## useR 2014 Slides for PSAboot and Version 1.1 on CRAN

July 3, 2014
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PSAboot is an R package to assist with bootstrapping propensity score methods. I gave a talk today at the useR! 2014 Conference. The slides can be downloaded from the PSAboot Github page or directly here. The package is described at jason.bryer.org/PSA...

## FRAMA Part III: Avoiding Countertrend Trading — A First Attempt

July 2, 2014
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This post will begin to experiment with long-term directional detection using relationships between two FRAMA indicators. By observing the relationship … Continue reading →