Ukraine election question

June 15, 2014
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Ukraine election question

Andrei Lopatenko writes: The top chart here represents the number of votes per a candidate as a function of the number of total bulletins counted. X is the total percentage of votes counted (5% means 5% of the total number of bulletins is read). Y is the percentage of votes per candidate blue Poroshenko, red […] The post Ukraine election question appeared first on Statistical Modeling, Causal Inference, and Social…

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Specifying complicated groups of time series in hts

June 15, 2014
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Specifying complicated groups of time series in hts

With the latest version of the hts package for R, it is now possible to specify rather complicated grouping structures relatively easily. All aggregation structures can be represented as hierarchies or as cross-products of hierarchies. For example, a hierarchical time series may be based on geography: country, state, region, store. Often there is also a separate product hierarchy: product groups, product types, packet size. Forecasts of all the different types…

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“Statistical Science and Philosophy of Science: where should they meet?”

June 14, 2014
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“Statistical Science and Philosophy of Science: where should they meet?”

Four score years ago (!) we held the conference “Statistical Science and Philosophy of Science: Where Do (Should) They meet?” at the London School of Economics, Center for the Philosophy of Natural and Social Science, CPNSS, where I’m visiting professor [1] Many of the discussions on this blog grew out of contributions from the conference, and conversations […]

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Trimmed Hedges

June 14, 2014
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Sorry about the title. It was the closest I could come to “Shattered Glass.” The subhead is “Pulitzer winner. Lefty hero. Plagiarist.” Chris Hedges is a reporter who apparently has been very busy for many years, in fact, according to this report by Christopher Ketcham he’s been so busy telling important things to the world […] The post Trimmed Hedges appeared first on Statistical Modeling, Causal Inference, and Social Science.

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He’s not so great in math but wants to do statistics and machine learning

June 14, 2014
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I received the following email from someone who wishes to remain anonymous: I am a longtime reader of your blog and it, along with other factors that I will explain briefly, has motivated to pursue a second masters degree in statistics and machine learning. The problem is, my math isn’t great. I understand statistics and […] The post He’s not so great in math but wants to do statistics and…

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Another 180 on Piketty’s Measurement

June 14, 2014
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My first Piketty Post unabashedly praised Piketty's measurement (if not his theory):"Piketty's book truly shines on the data side. ... Its tables and figures...provide a rich and jaw-dropping image, like a new high-resolution photo of a previously...

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RGolf: NGSL Scrabble

June 14, 2014
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RGolf: NGSL Scrabble

It is last part of RGolf before summer. As R excels in visualization capabilities today the task will be to generate a plot.We will work with NGSL data - a list of 2801 important vocabulary words for students of English as a second ...

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European talks. June-July 2014

June 14, 2014
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European talks. June-July 2014

For the next month I am travelling in Europe and will be giving the following talks. 17 June. Challenges in forecasting peak electricity demand. Energy Forum, Sierre, Valais/Wallis, Switzerland. 20 June. Common functional principal component models for...

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Identifying Pathways in the Consumer Decision Journey: Nonnegative Matrix Factorization

June 13, 2014
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Identifying Pathways in the Consumer Decision Journey: Nonnegative Matrix Factorization

The Internet has freed us from the shackles of the yellow page directory, the trip to the nearby store to learn what is available, and the forced choice among a limited set of alternatives. The consumer is in control of their purchase journey and can t...

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Health Care Costs Gone Wild

June 13, 2014
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Yet again I am amazed by the unscrupulous hubris of the US medical industry. On May 12th I went into a local dermatologist's office in MD to have a wart removed. The procedure was exceedingly simple and took no more than 20 minutes.  It involved ...

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The Oracle (2)

June 13, 2014
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The Oracle (2)

The World Cup is now under way, after an arguably fairly lacklustre performance by the host against a tough (if possibly a bit naive) Croatian team, still resulting in a 3-1 win for Brazil. I'll try and comment on our predictions for the first few...

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An Annotated Online Bioinformatics / Computational Biology Curriculum

June 13, 2014
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An Annotated Online Bioinformatics / Computational Biology Curriculum

Two years ago David Searls published an article in PLoS Comp Bio describing a series of online courses in bioinformatics. Yesterday, the same author published an updated version, "A New Online Computational Biology Curriculum," (PLoS Comput Biol 10(6):...

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World Cup pseudo-science

June 13, 2014
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Lee Sechrest pointed me to this news article by Vitomir Miles Raguz, “Brazil Won’t Win the World Cup. A European team will win again thanks to training and statistical analysis.” Hmmm . . . “statistical analysis.” This Raguz character better coordinate stories with Nate; it seems that the statistical experts are disagreeing . . . […] The post World Cup pseudo-science appeared first on Statistical Modeling, Causal Inference, and Social…

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What I do when I get a new data set as told through tweets

June 13, 2014
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What I do when I get a new data set as told through tweets

Hilary Mason asked a really interesting question yesterday: Data people: What is the very first thing you do when you get your hands on a new data set? — Hilary Mason (@hmason) June 12, 2014 You should really consider reading … Continue reading →

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Brazil’s Host Advantage

June 13, 2014
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Brazil’s Host Advantage

If history can tell us anything about the World Cup, it’s that the host nation has an advantage of all other teams. Evidence of this was presented last night as the referee in the Brazil-Croatia match unjustly ruled in Brazil’s favour on several occasions. But what it is the statistical evidence of a host advantage? […]

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Geometry, sensitivity, and parameters of the lognormal distribution

June 13, 2014
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Geometry, sensitivity, and parameters of the lognormal distribution

Today is my 500th blog post for The DO Loop. I decided to celebrate by doing what I always do: discuss a statistical problem and show how to solve it by writing a program in SAS. Two ways to parameterize the lognormal distribution I recently blogged about the relationship between […]

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trying to speed up Metropolis… and failing!

June 12, 2014
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trying to speed up Metropolis… and failing!

A while ago (but still after Iceland since I used the thorn rune as a math symbol!), I wrote the following post draft as a memo. Now that Marco Banterle, Clara Grazian and myself have completed our delayed acceptance paper, it may be of interest to some readers to see how a first attempt proved […]

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Stan is Turing Complete. So what?

June 12, 2014
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This post is by Bob Carpenter. Stan is Turing complete! There seems to a persistent misconception that Stan isn’t Turing complete.1, 2 My guess is that it stems from Stan’s (not coincidental) superficial similarity to BUGS and JAGS, which provide directed graphical model specification languages. Stan’s Turing completeness follows from its support of array data […] The post Stan is Turing Complete. So what? appeared first on Statistical Modeling, Causal…

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The Syrian p-value that I didn’t bother to calculate

June 12, 2014
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I posted something on the sister blog about the fake vote totals from the Syrian election. We know the numbers are fake from the official report, which reads: Speaker of the People’s Assembly, Mohammad Jihad al-Laham announced Wednesday that Dr. Bashar Hafez al-Assad won the post of the Syrian Arab Republic’s President for a new […] The post The Syrian p-value that I didn’t bother to calculate appeared first on…

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Example 2014.6: Comparing medians and the Wilcoxon rank-sum test

June 12, 2014
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Example 2014.6: Comparing medians and the Wilcoxon rank-sum test

A colleague recently contacted us with the following question: "My outcome is skewed-- how can I compare medians across multiple categories?" What they were asking for was a generalization of the Wilcoxon rank-sum test (also known as the Mann-Whitney...

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The First Nuclear Bomb, Bayesian Statistics, and the Progress of Science

June 12, 2014
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The yield from the first atomic bomb was classified, and might have remained so if some knucklehead hadn’t published a series of photos complete with scales and time stamps in Life magazine. This was enough to allow the physicist G. I. Taylor to ...

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The Poisson Transform for Unnormalised Statistical Models

June 12, 2014
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The Poisson Transform for Unnormalised Statistical Models

Nicolas Chopin has just arxived our manuscript on inference for unnormalised statistical models. An unnormalised statistical model whose likelihood function can be written where is easy to compute but the normalisation constant is hard. A lot of common models fall into that category, for example Ising models or restricted Boltzmann machines. Not having the normalisation […]

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Mathematics and Applied Statistics Lesson of the Day – The Harmonic Mean

Mathematics and Applied Statistics Lesson of the Day – The Harmonic Mean

The harmonic mean, H, for positive real numbers is defined as . This type of mean is useful for measuring the average of rates.  For example, consider a car travelling for 240 kilometres at 2 different speeds: 60 km/hr for 120 km 40 km/hr for another 120 km Then its average speed for this trip […]

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