Two months ago there was a discussion in the ESS mailing list about Emacs/ESS started by Paul Johnson, who claimed "Emacs Has No Learning Curve". While this sounds impossible, he really has some good points, e.g. he encourages beginners to look at the ... [Read more...]

Hurricane Sandy is shaping up to be a major, and very dangerous, meteorological event for the US's East coast. Naturally, everyone is looking for the latest information and forecasts. Fortunately, the wealth of public meteorological data available on the open web, combined with real-time on-the-ground updates via social media, means ... [Read more...]

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Millions of tweets, retweets and mentions are exchanged in Twitter everyday about very different subjects, events, opinions, etc. While aggregating this data over a time window might help to understand some properties of those processes in online social networks, the … Continue reading →   Related posts: Temporal networks with igraph and R (... [Read more...]

This two-part blog post I published a day ago required key-stats from Yahoo Finance for all the companies in the control group I created for my research.  I wanted all the key-stats pulled, arranged in a data-frame and then present them side-... [Read more...]

I don’t understand the website Pinterest, but it looks pretty (especially on the iPad), and an undergraduate student said it was the greatest thing since Facebook, so I thought I would give it a shot. The idea is that Pinterest … Continue reading → [Read more...]

When applying the stats::lag() function to a data frame, you probably expect it will pad the missing time periods with NA, but lag() doesn’t. For example: Nothing happened. Here is an alternative lag function made for this situation. It pads … Continue reading → [Read more...]

I recently posted an article on how to collate Wikipedia page views As there is a time component to this, it seemed appropriate to use the googleVis Package to visualize changes in page hits in the Google Motion chart For this exercise, I ran the wikiFun function covered in the ... [Read more...]

After a bit of a summer lull, the Montreal R User Group is meeting up again! We’re trying out a new venue this time. Notman House is the home of the web in Montreal. They hold hackathons and other tech user group meetups, and they are all around great ... [Read more...]

Terrain attributes can be derived by elevation values on a small neighbourhood of each DEM point.The major attributes can be calculated from the derivatives of the topographic surface. These derivatives measure the rate of change in elevation in relati... [Read more...]

Routino is a set of libraries that enable road based route calculations to be conducted over OpenStreetMap data. I have been using them extensively over the past six months for a project looking at CO2 emissions and the commute to school. Although Routino was designed to run under Linux, it ... [Read more...]

The Brownian motion is certainly the most famous stochastic process (a random variable evolving in the time). It has been the first way to model a stock option price (Louis Bachelier's thesis in 1900).The reason why is easy to understand, a Brownian mo... [Read more...]

As the entire East Coast gets soaked by Hurricane Sandy, I can’t help but think that this is the perfect time to…take a course online! Well, as long as you have electricity, that is. I live in a heavily tree-lined area and so it’s onl... [Read more...]

In the early days of the discipline of statistics, R.A. Fisher argued with great vehemence against Egon Pearson (and Jerzy Neyman) over the foundational notions supporting statistical inference. The personal invective recorded is somewhat amusing an... [Read more...]

Given that Sampdoria have lost their fourth game in a row, I am not really interested in football any more (as of yesterday, I actually find it a very boring game and think we should focus on real sports $-$ of course if we manage to break the cra... [Read more...]

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Should you use daily or monthly returns to estimate volatility? Does garch explain why volatility estimated with daily data tends to be bigger than if it is estimated with monthly data? Previously There are a number of previous posts — with the variance compression tag — that discuss the phenomenon of volatility ... [Read more...]

It is fairly clear from the duration between this and my last post that various other things have been getting in the way of updates. Anyway, I shall try and post a few updates on news and things I have been working on recently in the coming weeks before getting ... [Read more...]

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I have been traveling during the last two weeks. I visited Fred Hutchinson Cancer Research Center on Oct 16 and the Department of Biostatistics at Johns Hopkins at the invitation of Simply Statistics on Oct 23. Today Christian Robert was visiting our department at Iowa State, and I also talked to him. ... [Read more...]