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Constructing a Word Cloud for ICML 2015

2015-07-10     Conference

Word clouds have become a bit cliché, but I still think that they have a place in giving a high level overview of the content of a corpus. Here are the steps I took in putting together the word cloud for the International Conference on Machine Learning (2015). Read more »

ICML 2015 (Lille, France): Day 5 (Workshops)

2015-07-10     Conference

ICML 2015 (Lille, France): Day 4

2015-07-10     Conference

Sundry notes from the fourth day of the International Conference for Machine Learning (ICML 2015) in Lille, France. Some of this might not be entirely accurate. Caveat emptor. Celeste: Variational inference for a generative model of astronomical images (Jeffrey Regier, Andrew Miller, Jon McAuliffe, Ryan Adams, Matt Hoffman, Dustin Lang, David Schlegel, Prabhat) Colour modelled as a 4 dimensional vector. The Physics (Planck’s Law) places some constraints on the components of these vectors. Read more »

Data Science and Selling Shoes

2015-07-09

ICML 2015 (Lille, France): Day 3

2015-07-08     Conference

Selected scribblings from the third day at the International Conference for Machine Learning (ICML 2015) in Lille, France. I’m going out on a limb with some of this, since the more talks I attend, the more acutely aware I become of my limited knowledge of the cutting edge of Machine Learning. Caveat emptor. Adaptive Belief Propagation (Georgios Papachristoudis, John Fisher) Belief Propagation describes the passage of messages across a network. Read more »

ICML 2015 (Lille, France): Day 2

2015-07-08     Conference

Some notes from the second day at the International Conference for Machine Learning (ICML 2015) in Lille, France. Don’t quote me on any of this because it’s just stuff that I jotted down during the course of the day. Also much of the material discussed in these talks lies outside my field of expertise. Caveat emptor. Two Big Challenges in Machine Learning (Léon Bottou) Machine Learning is an Exact Science. Read more »

ICML 2015 (Lille, France): Day 1 (Tutorials)

2015-07-07     Conference

Started the day with a run through the early morning streets of Lille. This city seems to wake up late because it was still nice and quiet well after sunrise. Followed by a valiant attempt to sample everything on the buffet breakfast. I’ll know where to focus my attention tomorrow. ICML2015 The first day of the International Conference on Machine Learning (ICML 2015) in Lille consisted of tutorials in two parallel streams. Read more »

Review: Machine Learning with R Cookbook

2015-07-03     R Machine Learning Book Review

“Machine Learning with R Cookbook” by Chiu Yu-Wei is nothing more or less than it purports to be: a collection of 110 recipes for applying Data Analysis and Machine Learning techniques in R. I was asked by the publishers to review this book and found it to be an interesting and informative read. It will not help you understand how Machine Learning works (that’s not the goal!) but it will help you quickly learn how to apply Machine Learning techniques to you own problems. Read more »

Flashes from the Ashes: Volcanic Lightning

2015-07-03

Excel: Copying with Relative Links

2015-06-26     Excel

Amazon EC2: Adding Swap

2015-06-19     AWS

So, after upgrading to R 3.2.0 on my EC2 instance, I was installing newer versions of various packages and I ran into a problem with dplyr: virtual memory exhausted! Seemed like a good time to add some swap. Read more »

Amazon EC2: Upgrading R

2015-06-19     R AWS

After installing R and Shiny on my EC2 instance I discovered that the default version of R was a little dated and I wanted to update to R 3.2.0. It’s not terribly complicated, but here are the steps I took. When you launch R you should find that it is the sparkling new version. Now you will want to update all of the packages too, so launch R (as root) and then do: Read more »

Disney: Quality over Quantity

2015-06-15

I read an interesting article in the 10 June 2015 edition of The Wall Street Journal. The graphic below concisely illustrates the focused strategy being adopted by Disney: a steady decline in the number of movies released per year accompanied by a steady ascent in operating margin. Read more »

R Recipe: RStudio and UNC Paths

2015-06-04     R

RStudio does not like Uniform Naming Convention (UNC) paths. This can be a problem if, for example, you install it under Citrix. The solution is to create a suitable environment file. Read more »

Hosting Shiny on Amazon EC2

2015-05-30     R AWS

I recently finished some work on a Shiny application which incorporated a Random Forest model. The model was stored in a RData file and loaded by server.R during initialisation. This worked fine when tested locally but when I tried to deploy the application on shinyapps.io I ran into a problem: evidently you can only upload server.R and ui.R files. Nothing else. Read more »

Comrades Marathon Medal Predictions

2015-05-28     R running

R Recipe: Aligning Axes in ggplot2

2015-05-27     R

Faceted plots in ggplot2 are phenomenal. They give you a simple way to break down an array of plots according to the values of one or more categorical variables. But what if you want to stack plots of different variables? Not quite so simple. But certainly possible. I gathered together this solution from a variety of sources on stackoverflow, notably this one and this other one. A similar issue for vertical alignment is addressed here. Read more »

R Recipe: Reordering Columns in a Flexible Way

2015-05-16     R

Recent Common Ancestors: Simple Model

2015-05-15     R

An interesting paper (Modelling the recent common ancestry of all living humans, Nature, 431, 562–566, 2004) by Rohde, Olson and Chang concludes with the words: Read more »

R Recipe: Making a Chord Diagram

2015-05-09

With the circlize package, putting together a Chord Diagram is simple. library(circlize) library(RColorBrewer) # Create a random adjacency matrix # adj = matrix(sample(c(1, 0), 26**2, replace = TRUE, prob = c(1, 9)), nrow = 26, dimnames = list(LETTERS, LETTERS)) adj = ifelse(adj == 1, runif(26**2), 0) chordDiagram(adj, transparency = 0.4, grid.col = "midnightblue", col = colorRamp2(seq(0, 1, 0.2), brewer.pal(6, "Blues")))

Comrades Marathon Finish Predictions

2015-04-23     R Running

Comrades Runners Disqualified: I'm Not Convinced

2015-04-16     Running

Apparently 14 runners have been disqualified for failing to complete the full distance at the 2012 and 2013 Comrades Marathons. I’m not convinced. Read more »

Encyclopaedia: Meteorites in Antarctica

2015-04-13

A contribution which I wrote for Antarctica and the Arctic Circle: A Geographic Encyclopedia of the Earth’s Polar Regions. Read more »

A Sankey Plot with Uniform Coloured Edges

2015-04-07     R

Following up on my previous post about generating Sankey plots with the riverplot package. It’s also possible to generate plots which have constant coloured edges. Read more »

Encyclopaedia: Discovery Expedition

2015-04-06

A contribution which Claire and I wrote for Antarctica and the Arctic Circle: A Geographic Encyclopedia of the Earth’s Polar Regions. Read more »

Bags, Balls and the Hypergeometric Distribution

2015-04-03     R

Comrades Marathon Pacing Chart: Up Run

2015-04-01     Excel Running

I’ve updated my Comrades Marathon pacing chart to include both the Up and Down runs. You can grab it here. The data for this year’s race are not yet finalised (I think we will be running 87 km), but you can make changes when it’s all confirmed. Read more »

The Price of Fuel: How Bad Could It Get?

2015-04-01     R

The cost of fuel in South Africa (and I imagine pretty much everywhere else) is a contentious topic. It varies from month to month and, although it is clearly related to the price of crude oil and the exchange rate, various other forces play an influential role. Read more »

Creating Charts with Easel.ly

2015-03-31

Encyclopaedia: Geospace

2015-03-30

A contribution which I wrote for Antarctica and the Arctic Circle: A Geographic Encyclopedia of the Earth’s Polar Regions. As a side note, I am normally quite pedantic about “Earth” and “Sun” being capitalised but the editor of the Encyclopaedia evidently had different views on this point. Read more »