One of the most straightforward examples of how we use Bayes to update our beliefs as we acquire more information can be seen with a simple Bernoulli process. That is, a process which has only two  possible outcomes. Probably the most commonly thought of example is that of a coin ... [Read more...]

In Using Google Spreadsheets as a Database Source for R, I described a simple Google function for pulling data into R from a Google Visualization/Chart tools API query language query applied to a Google spreadsheet, given the spreadsheet key and worksheet ID. But how do you get a list ... [Read more...]

I couldn’t contain myself (other more pressing things to do, but…), so I just took a quick time out and a coffee to put together a quick and dirty R function that will let me run queries over Google spreadsheet data sources and essentially treat them as database tables (... [Read more...]

I spent a chunk of today trying to get my thoughts in order for a keynote presentation at next week’s The Difference that Makes a Difference conference. The theme of my talk will be on how visualisations can be used to discover structure and pattern in data, and as ... [Read more...]

As September draws nearer, my mind inevitably turns away from my lofty (and largely unmet) summer research goals, and toward teaching.  This semester I will be trying out a teaching technique using live data collection and analysis as a tool to encourage student engagement.  The idea is based on the ... [Read more...]

This summer, we have been told that some financial series broke some records (here, in French) For instance, the French CAC40 had negative return for 11 consecutive days (which has never been seen, so far). __ library(tseries)__ x [Read more...]

Tweet When I first started using R, one of the things that attracted me was its claim to be an object-oriented programming (OOP) language. Coming from a Java background, I was used to designing software with OOP concepts like encapsulation and inheritance but, when I turned my hand to R, ... [Read more...]

Ever have a regression model where the coefficients don't make sense? I've been trying to predict electricity and gas consumption from daily activity schedules but a simple linear regression kept saying that demands should go down the more an activity is performed. Fortunately I found the nnls package and show ... [Read more...]

How many different dimensions (or “columns” in a dataset where each row represents a different sample and each column a different measurement taken as part of that sample) can you plot on a chart? Two are obvious: X and Y values, which are ideal for representing continuous numerical variables. If ... [Read more...]

Another way for the database challenged (such as myself!) for merging two datasets that share at least one common column… This recipe using the cross-platform stats analysis package, R. I use R via the R-Studio client, which provides an IDE wrapper around the R environment. So for example, here’s ... [Read more...]

Looking over the sector times from the qualifying session for tomorrow’s Hungarian Grand Prix, I noticed that Vettel was only fastest in one of the sectors. Whilst looking for an easy way of shaping an R data frame so that I could plot categorical values sector1, sector2, sector3 on ... [Read more...]

I wish I knew everything about R. I wish I could vectorise in my sleep. I wish there were perfect R packages out there to solve all my data transformation problems. I wish there were perfect data. If I were Paul Graham, would I ever write code like the... [Read more...]

One of my teaching roles is in an introductory Genetics course, where first year students are presented with a wide range of new ideas at a relatively fast pace.  It seems that often, students choose to take a memorization approach to learning the material, rather than taking the chance to ... [Read more...]

R books are now showing up in the dollar bin. That’s a good sign! [Read more...]

Last week I attended the OU Statistics conference on Visualisation and Presentation in Statistics (VIPS) (notes: here and here) One of the things that struck me from conversations and some of the presentations was that statistics – and in particular public engagement around statistics – appears to be lagging science efforts in ... [Read more...]

In the early stages of a literature review, you may have hundreds of papers and not know how to even begin sorting through them. In this post, I show you how to perform a two-stage clustering analysis with R so that you can identify the main groups within your data, ... [Read more...]

Consider a random pair of binary responses, i.e. with taking values 1 or 2. Assume that probability can be function of some covariates . The Gaussian vector latent structure A standard model is based a latent Gaussian structure, i.e. there exi... [Read more...]

A lot of weird facts (?) can be found on the internet. For instance, about the height of the winner of Presidential elections in the US: the taller always win... "Still, being short does, on average, hurt a person's prospects...The tall guy gets th... [Read more...]

My son would be extremely proud if I tell him I can spend hours building robots. Well, my robots are not as fancy as Dr Tenma's, but they usually do what I ask them to do. For instance, it is extremely simple to build a robot with R, to extract ... [Read more...]

I am not a big fan of those ceremonies, where some actors pretend that they are extremely happy to be there, and then some win a trophy, some don't, and those who win start to cry, and those who did not get a trophy try to pretend that they are ... [Read more...]