Blog Archives

Forecasting workshop: Switzerland, June 2011

December 6, 2010
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Forecasting workshop: Switzerland, June 2011

I will be running a workshop on Statistical Forecasting: Principles and Practice in Switzerland, 20-22 June 2011. Check out the venue: Waldhotel Doldenhorn, Kandersteg! So if you fancy a trip to the beautiful Swiss Alps next June, read on… Outline Forecasting is required in many situations: deciding whether to build another power generation plant in

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Data visualization videos

November 29, 2010
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Probably everyone has seen Hans Rosling’s famous TED talk by now. I recently came across a couple of other exceptional talks on data visualization: Hans Rosling again: Let my dataset change your mindset. If only all statistics lecturers were this dynamic! David McCandless: The beauty of data visualization. Not so exciting as Hans, but some great

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Initializing the Holt-Winters method

November 29, 2010
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Initializing the Holt-Winters method

The Holt-Winters method is a popular and effective approach to forecasting seasonal time series. But different implementations will give different forecasts, depending on how the method is initialized and how the smoothing parameters are selected. In this post I will discuss various initialization methods. Suppose the time series is denoted by and the seasonal period

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Forecast estimation, evaluation and transformation

November 9, 2010
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Forecast estimation, evaluation and transformation

I’ve had a few emails lately about forecast evaluation and estimation criteria. Here is one I received today, along with some comments. I have a rather simple question regarding the use of MSE as opposed to MAD and MAPE. If the parameters of a time series model are estimated by minimizing MSE, why do we

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CrossValidated launched!

November 4, 2010
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CrossValidated launched!

The CrossValidated Q&A site is now out of beta and the new design and site name is live. New design The new design looks great, thanks to Jin Yang, our designer-in-residence. Note the normal density icon for accepted answers and the site icon depicting a 5-fold cross-validation (light green for the test set and dark

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Different results from different software

October 26, 2010
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I’ve had a few questions on this topic lately. Here is an email received today: I use Eviews to estimate time series, but I have been checking out R recently, and your Forecast package. I cannot understand why 2 similar equations in Eviews and R are giving different estimated output. Your insights will be invaluable

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How to avoid annoying a referee

October 22, 2010
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It’s not a good idea to annoy the referees of your paper. They make recommendations to the editor about your work and it is best to keep them happy. There is an interesting discussion on stats.stackexchange.com on this subject. This inspired my own list below. Explain what you’ve done clearly, avoiding unnecessary jargon. Don’t claim

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Happy World Statistics Day!

October 19, 2010
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The United Nations has declared today “World Statistics Day”. I’ve no idea what that means, or why we need a WSD. Perhaps it is because the date is 20.10.2010 (except in North America where it is 10.20.2010). But then, what happens from 2013 to 2099? And do we just forget the whole idea after 3112?

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Animated plots in R and LaTeX

October 12, 2010
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Animated plots in R and LaTeX

I like to use animated plots in my talks on functional time series, partly because it is the only way to really see what is going on with changes in the shapes of curves over time, and also because audiences love them! Here is how it is done. For LaTeX, you need to create every

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Why R is better than Excel for teaching statistics

October 4, 2010
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Why R is better than Excel for teaching statistics

This was the topic of a recent conversation on the Australian and New Zealand R mailing list. Here is an edited list of some of the comments made. R is free. R is well-documented. R runs (really well) on *nix as well as Windows and Mac OS. R is open-source. Trust in the R software

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