This test is the first attempt to seriously assess the ability of individuals to survive a zombie apocalypse.  This test is administered using the R powered open-source testing platform Concerto developed at the University of Cambridge. The t... [Read more...]

I just updated my short review on Bayesian computational tools I first wrote in April for the Annual Review of Statistics and Its Applications. The coverage is quite restricted, as I took advantage of two phantom papers I had started a while ago, one with Jean-Michel Marin, on hierarchical Bayes ... [Read more...]

At our last Davis R Users’ Group meeting of the quarter, Dave Harris gave a talk on how to use the bbmle package to fit mechanistic models to ecological data. Here’s his script, which I ran throgh the spin function in knitr:

<span># Load data</span>
<span>library</span>(emdbook)

## Loading required package: MASS Loading required package: lattice

<span>library</span>(bbmle)

## Loading required package: stats4

<span>data</span>(ReedfrogFuncresp)
<span>plot</span>(ReedfrogFuncresp, <span>xlim =</span> <span>c</span>(<span>0</span>, <span>100</span>), <span>xaxs =</span> <span>"i"</span>)

Statistical models ... [Read more...]

[This article was first published on Oracle R Enterprise, and kindly contributed to R-bloggers]. (You can report issue about the content on this page here) Want to share your [Read more...]

Previously I wrote about performing polynomial regression and also about calculating marginal likelihoods. The data in the former and the calculations of the latter will be used here to exemplify model selection. Consider data generated by and suppose we wish to fit a polynomial of degree 3 to the data. There ... [Read more...]

It is getting easier to get data directly into R from the web. Often R packages that retrieve data from the web return useful R data structures to users like a data.frame. This is a good thing of course to make things user friendly. However, what if you want ... [Read more...]

for the unlucky among us born without a portuguese mother tongue, the pesquisa de orcamentos familiares (pof) translates to survey of household budgets.  this data set captures brazilian family consumption habits, allocation of expenses, and incom... [Read more...]

or, Is the Seattle Mariners outfield a disaster?The BackstoryEarlier this week (2013-06-10), a blog post by Dave Cameron appeared at USS Mariner under the title “Maybe It's Time For Dustin Ackley To Play Some Outfield”. In the first paragraph, Cameron describes to the Seattle Mariners outfield this season ... [Read more...]

Introduction Recently, I began a series on exploratory data analysis (EDA), and I have written about descriptive statistics, box plots, and kernel density plots so far.  As previously mentioned in my post on box plots, there is a way to combine box plots and kernel density plots.  This combination results ... [Read more...]

After being busy the last two weeks teaching and attending academic conferences, I finally found some time to do what I love, program data visualizations using R. After being interested in Shiny for a while, I finally decided to pull the trigger and build my first Shiny app! I wanted ... [Read more...]

Similar to the back propagation neural network, the general regression neural network (GRNN) is also a good tool for the function approximation in the modeling toolbox. Proposed by Specht in 1991, GRNN has advantages of instant training and easy tuning. A GRNN would be formed instantly with just a 1-pass training ... [Read more...]

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Getting Expected Shortfall given the standard deviation or Value at Risk. Previously There have been a few posts about Value at Risk and Expected Shortfall. Properties of the stable distribution were discussed. Scaling One way of thinking of Expected Shortfall is that it is just some number times the standard ... [Read more...]

Two weeks ago I described car data, among which weight distribution of cars in Netherlands. At that time it was purely plots. In the mean time I decided I wanted to model trends. As a first step of that, I decided to fit distributions for these da... [Read more...]

Feeding Schedule While on paternity leave I had an opportunity to test out periodic smoothing splines (within the framework of generalized additive models) on an interesting time-series-- an infant's feeding schedule. read more [Read more...]

Some days ago H. Wickham (Chief Scientist of the RStudio company) posted an article about the RStudio CRAN mirror with …Continuar leyendo » [Read more...]

At datadolph.in, we are constantly crunching through large amounts of data.  We are designing unique and innovative ways to process large datasets on a single node and use distributed computing only when single node computing become... [Read more...]

On a recent flight I was bored waiting for the plane to land and I tried out the electronic sudoku game that they had offered.  I found the game surprisingly interesting as I realized that it is far more entertaining when you cannot use paper or p... [Read more...]

This post is about a practical application of a topic I discuss in my book. In my book, I prove …Continue reading » [Read more...]

R package developer (and R-bloggers editor) Tal Galili just published the answers to a question many R users have asked: which are the most popular R packages? He wrote some R code to rank the top 100 packages by number of downloads. Here's the top 10: The source data are the download ... [Read more...]