# Blog Archives

## A quick primer on split-apply-combine problems

December 16, 2011
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I’ve just answered my hundred billionth question on Stack Overflow that goes something like I want to calculate some statistic for lots of different groups. Although these questions provide a steady stream of easy points, its such a common and basic data analysis concept that I thought it would be useful to have a document

## Interactive graphics for data analysis

September 1, 2011
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I got a copy of Martin Theus and Simon Urbanek’s Interactive Graphics for Data Analysis a couple of years ago, whence it’s been sat on my bookshelf. Since I’ve recently become a self-proclaimed expert on interactive graphics I thought it was about time I read the thing. Which is exactly what I did last weekend

## Nomograms everywhere!

August 30, 2011
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At useR!, Jonty Rougier talked about nomograms, a once popular visualisation that has fallen by the wayside with the rise of computers. I’d seen a few before, but hadn’t understood how they worked or why you’d want to use them. Anyway, since that talk I’ve been digging around in biology books from the 60s and

## Anonymising data

August 23, 2011
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There are only three known jokes about statistics in the whole universe, so to complete the trilogy (see here and here for the other two), listen up: Three statisticians are on a train journey to a conference, and they get chatting to three epidemiologists who are also going to the same place. The epidemiologists are

## More useless statistics

August 22, 2011
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Over at the ExploringDataBlog, Ron Pearson just wrote a post about the cases when means are useless. In fact, it’s possible to calculate a whole load of stats on your data and still not really understand it. The canonical dataset for demonstrating this (spoiler alert: if you are doing an intro to stats course, you

## useR2011 highlights

August 18, 2011
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useR has been exhilarating and exhausting. Now it’s finished, I wanted to share my highlights. 10. My inner twelve year old schoolgirl swooning and fainting with excitement every time I chatted with a member of R-core. 9. Patrick Burns declaring that his company consists of himself and his two cats. And that one of the

## useR2011 Easy interactive ggplots talk

August 17, 2011
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I’m talking tomorrow at useR! on making ggplots interactive with the gWidgets GUI framework. For those of you at useR, here is the code and data, so you can play along on your laptops. For everyone else, I’ll make the slides available in the next few days so you can see what you missed. Note

## Stop! (In the name of a sensible interface)

August 12, 2011
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In my last post I talked about using the number of lines in a function as a guide to whether you need to break it down into smaller pieces. There are many other useful metrics for the complexity of a function, most notably cyclomatic complexity, which tracks the number of different routes that code can

## Monster functions (Raaargh!)

August 12, 2011
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It’s widely considered good programming practice to have lots of little functions rather than a few big functions. The reasons behind this are simple. When your program breaks, it’s much nicer to debug a five line function than a five hundred line function. Additionally, by breaking up your code into little chunks, you often find

## The Stats Clinic

July 27, 2011
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Here at HSL we have a lot of smart kinda-numerate people who have access to a lot of data. On a bad day, kinda-numerate includes myself, but in general I’m talking about scientists who have have done an introductory stats course, but not much else. When all you have is a t-test, suddenly everything looks