Introducing Customer Lifetime Value (CLV) Customer Lifetime Value is “the present value of the future cash flows attributed to the customer during his/her entire relationship with the company.”1 There are different kinds of formulas, from simplified to advanced, to calculate CLV.  But the following one might be the one ... [Read more...]

I like to use Goodreads to keep track of which books I'm reading (and not reading). They very helpfully sent me an e-mail to inform me how many books I've read so far in 2013. The number is 19. Hardly an impressive number, but between job, family and trying to develop my ... [Read more...]

Where I reported yesterday the initial steps of an client R package for Open PHACTS, I can now report the first pharmacology data import: [Read more...]

Introduction Some people have come to believe that Julia’s vectorized code is unusably slow. To correct this misconception, I outline a naive benchmark below that suggests that Julia’s vectorized code is, in fact, noticeably faster than R’s vectorized code. When experienced Julia programmers suggest that newcomers should ... [Read more...]

The ggmap package can be used to access maps from the Google Maps API and there are a number of examples on various statistics related blogs. These include here, here and here. The ggmap package has a function get_map that can download maps from various sources including Google Maps. ... [Read more...]

Part 1: coastal applications The oce package has a world coastline file that is visibly crude on a scale suitable for continental-shelf work.  At the cost of about 1 Mbyte of storage, a candidate for a replacement is a 1:10million scale version downloaded from naturalearthdata.com (full link below). As illustrated below ... [Read more...]

The Centre for Forecasting at Lancaster University is conducting some research on judgmental forecasting and model selection. They hope to compare the performance of judgmental model selection with statistical model selection, in order to learn how to best design forecasting support systems. They would like forecasting students, practitioners and researchers ... [Read more...]

I drove through Tennessee today. Despite having grown up in Kentucky, I had never really noticed the Tennessee flag, but earlier this year, while in Nashville, I saw it and thought it was one of the cooler state flags. I downloaded a PNG file of the flag from wikicommons and ... [Read more...]

Nothing much going to say about it, and just to report some progress: [Read more...]

It's been a while since my last video, with good reason: I started a full time job as a senior statistician about 2 months ago! Not that I spend my entire day coding in R, but I wouldn't be nearly as useful if I didn't know how to use it. Anyway, ... [Read more...]

The winter solstice has been on many minds lately. The days are about to start getting longer … but just how fast will they do that? This post provides R that calculates and graphs day length and its variation, using uniroot() to find sunrises and sunsets as indicated by solar altitude ... [Read more...]

Introduction The sunAngle() function in the oce package provides a handy way to determine sunrise/sunset azimuth angles, and this is used to find alignments for the winter solstice in Halifax, NS. Methods First, set up the problem; these may be the only lines that need editing for other places ... [Read more...]

The illuminated fraction of the moon can be calculated with moonAngle() in the oce package, as illustrated graphically and in R code below.

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library(oce) par(mar=c(3, 3, 1, 1), mgp=c(2, 0.7, 0)) # tighten margins t [Read more...]

Some time ago, I was doing some analysis and trying to determine whether or not there was a predictive variable for a binomial response. I ran logistic regressions for about half a dozen variables in different combinations and nothing showed a fit of any significance. Well, almost nothing. I had ... [Read more...]

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I am currently following a course on probability theory in coursera (https://www.coursera.org/course/probas) and I’ve seen some graphs concerning the outcome of some dice throws. Being an R-nerd I wrote a little function to do this in R. This is nothing fancy just I find ... [Read more...]

I'm heading out on vacation shortly but don't worry: we have a fantastic series of guest bloggers contributing to the Revolution blog for the next 3 weeks. We'll have posts from the Revolution Analytics development team, contributions from prominent R community members, and industry experts. And I'll still pop in from ... [Read more...]

I was looking on twitter and noticed a lot of people talking about Duck Dynasty and then talking about the consequences to A&E.  I was curious on what was being said.  I mined Twitter for #A&E and #duckdynasty and got the following wo... [Read more...]

Carrying on with the multi-level model, I'm going to look at the paid and incurred workers comp losses for a large number of insurance companies. This is a similar exercise to what I did last night, but I'm now working with real, rather than simulated data and the stochastic process ... [Read more...]

In a recent email to the Rcpp and lme4 mailing lists, Doug Bates announced that was turning away from R, Rcpp, lme4 and hence also RcppEigen for which he had been both the primary author and maintainer. This is huge loss for the R community. I have... [Read more...]