The statistical software R has an ever-expanding array of packages that provide pre-programmed functions and datasets. One such package is named Lahman, bundling the contents of the Lahman database into a quick-and-easy resource for R users. In addition to the data tables, the package resources also contain a variety of ... [Read more...]

This is one of my favorite charts, it easily allows one to see how many predictions are right, and it allows one to see where the wrong ones are as well. It is the equivalent of a confusion matrix, but sometimes a picture is worth a thousand words. Some sample ... [Read more...]

Next on modelling survival data from Veterinary Epidemiologic Research: semi-parametric analyses. With non-parametric analyses, we could only evaluate the effect one or a small number of variables. To evaluate multiple explanatory variables, we analyze data with a proportional hazards model, the Cox regression. The functional form of the baseline hazard ... [Read more...]

Last week, we had a discussion with some colleagues about the fact that – in order to prepare for the SOA exams – we did not have time (so far) to mention results on extreme values in our actuarial program. I did gave an introduction in my nonlife actuarial models class, but ... [Read more...]

Before you can analyze data, it must be in the right form. Join Revolution Analytics and me this June 21st for a 4-hour webinar that shows how to perform the most commonly used data management tasks in R. We will work through … Continue reading → [Read more...]

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I'm pleased to announce that the new version 0.80 of PluginR has just been released (as usual, available as a Tiki Mod) with a few minor bugs fixed, and a couple of new interesting features added: PluginR now uses a caching mechanism extending the ... [Read more...]

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Following on from last week's post, here are my slides on using googleVis on shiny from the Advanced R workshop at Lancaster University, 21 May 2013. googleVis on shiny Again, I wrote my slides in RMarkdown and I used slidify to create the HTML5 presentation. Unfortunately you may have to reload the ... [Read more...]

Sudoku is nowadays probably the most widespread puzzle game in the world. As such, it has an interesting variety of solving techniques, not just with paper and pencil but also with computers. Of course, I am not the first one … Continue reading → [Read more...]

I subscribe to the Ensembl blog and found, in my feed reader this morning, a post which linked to the Variant Effect Predictor (VEP). The original blog post, strangely, has disappeared. Not to worry: so, the VEP takes genotyping data in one of several formats, compares it with the Ensembl ... [Read more...]

  How long does your Oracle RMAN backup take to complete?  How does this vary over time?  Are there patterns by week, week of month, or day of week?   The gist below can help you evaluate questions like these.… Read more › [Read more...]

In a paper arXived on Friday, Roberto Fontana relates the generation of Sudoku grids to the one of Latin squares (which is unsurprising) and to maximum cliques of a graph (more surprising). The generation of a random Latin square proceeds in three steps: generate a random Latin square L with ... [Read more...]

If you're thinking about starting a project (for example, a report or paper) using the R language for analysis, the Nice R code blog has some great advice. Following the principles of reproducible research, Macquarie University postdocs Rich FitzJohn and Daniel Falster suggest: Creating a directory structure to separate R ... [Read more...]

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In this blogpost, I will be talking briefly about Predictive Analytics and why it holds value from a web analytics perspective. Broadly speaking, Predictive Analytics is a set of methodologies that assist us in anticipating customer behavior. The customer behavior of interest could be anything ranging from spend, buying habits, ... [Read more...]

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I just finished fixing (hopefully all) the problems in the knitr book returned from the copy editor. David Smith has kindly announced this book before I do. I do not have much to say about this book: almost everything in the book can be found in the on... [Read more...]

When I first learned about Granger-causality this past February, I was bemused and quite skeptical of the whole procedure.  I felt it belonged on the scrapheap of impractical academic endeavors, preferring to possibly use an ARIMA transfer function model for the same task.  However, several contemporaries threw the red challenge ... [Read more...]