momentify R package at BAYSM14

September 20, 2014
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$momentify R package at BAYSM14$

I presented an arxived paper of my postdoc at the big success Young Bayesian Conference in Vienna. The big picture of the talk is simple: there are situations in Bayesian nonparametrics where you don’t know how to sample from the posterior distribution, but you can only compute posterior expectations (so-called marginal methods). So e.g. you cannot provide credible intervals. […]

Mini-tour

September 19, 2014
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The last two days have been kind of a very interesting mini-tour for me \$-\$ yesterday the Symposium that we organised at UCL (the picture on the left is not a photo taken yesterday) and today the workshop on efficient methods for value of inf...

Least Squares, Perfect Multicollinearity, & Estimable Functions

September 19, 2014
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This post is essentially an extension of another recent post on this blog. I'll assume that you've read that post, where I discussed the problem of solving linear equations of the form Ax = y, when the matrix A is singular.Let's look at how this proble...

What does CNN have in common with Carmen Reinhart, Kenneth Rogoff, and Richard Tol: They all made foolish, embarrassing errors that would never have happened had they been using R Markdown

September 19, 2014
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Rachel Cunliffe shares this delight: Had the CNN team used an integrated statistical analysis and display system such as R Markdown, nobody would’ve needed to type in the numbers by hand, and the above embarrassment never would’ve occurred. And CNN should be embarrassed about this: it’s much worse than a simple typo, as it indicates […]

The frequency of letters in an English corpus

September 19, 2014
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It's time for another blog post about ciphers. As I indicated in my previous blog post about substitution ciphers, the classical substitution cipher is no longer used to encrypt ultra-secret messages because the enciphered text is prone to a type of statistical attack known as frequency analysis. At the root […]

Visualizing Publicly Available US Government Data Online

September 19, 2014
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Brightpoint Consulting recently released a small collection of interactive visualizations based on open, publicly available data from the US government. Characterized by a rather organic graphic design style and color palette, each visualization makes...

The New Consumer Requires an Updated Market Segmentation

September 18, 2014
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The new consumer is the old consumer with more options and fewer prohibitions. Douglas Holt calls it the postmodern market defined by differentiation: "consumer identities are being fragmented, proliferated, recombined, and turned into salabl...

"Inverting" Singular Matrices

September 18, 2014
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You can only invert a matrix if that matrix is non-singular. Right? Actually, that's wrong.You see, there are various sorts of inverse matrices, and most of them apply to the situation where the original matrix is singular. Before elaborating on t...

The Disappearing Planet: Comparing the Extinction Rates of Animals

September 18, 2014
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The subtly designed A Disappearing Planet [propublica.org] by freelance data journalist Anna Flagg reveals the extinction rates of animals, caused by a variety of human-caused effects, including climate change, habitat destruction and species displace...

Shamer shaming

September 18, 2014
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This post is by Phil Price. I can’t recall when I first saw “shaming” used in its currently popular sense. I remember noting “slut shaming” and “fat shaming” but did they first become popular two years ago? Three? At any rate, “shaming” is now everywhere…and evidently it’s a very bad thing. When I first saw […]

Scottish Independence : Bing Predicts ‘No’

September 18, 2014
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Bing's prediction team has a feature live on the site right now that predicts Scotland will not become an independant nation as a result of today's referendum.

Palko’s on a roll

September 18, 2014
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I just wanted to interrupt our scheduled stream of posts to link to a bunch of recent material from Mark Palko: At least we can all agree that ad hominem and overly general attacks are bad: A savvy critique of the way in which opposition of any sort can be dismissed as “ad hominem” attacks. […]

p value from likelihood ratio test is STILL not the same as p value from maximum likelihood estimate

September 18, 2014
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In yesterday's post, I described two ways for finding a p value for a parameter, and pointed out that the two ways lead to different p values. As an example, I considered the slope parameter in simple linear regression. One way to get a p value for the...

The Front-End of Methods Training

September 18, 2014
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Based on my own experience and interactions with other professors and students, most methods training in political science starts with a “baby stats” course, continues into a more detailed course on linear models, and finishes with a fairly rigorous course on the generalized linear model that includes a grab bag of the latest and greatest […]

Common sense and statistics

September 18, 2014
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-+*College courses often begin by trying to weaken your confidence in common sense. For example, a psychology course might start by presenting optical illusions to show that there are limits to your ability to perceive the world accurately. I’ve seen at least one physics textbook that also starts with optical illusions to emphasize the need […]

Fun with .Rprofile and customizing R startup

September 18, 2014
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Over the years, I've meticulously compiled–and version controlled–massive and extensive configuration files for virtually all of my most used utilities, most notably vim, tmux, and zsh. In fact, one of the only configurable utilities for which I had no special… Continue reading →

p value from likelihood ratio test is not the same as p value from maximum likelihood estimate

September 18, 2014
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In a post of a few hours ago, I pointed out that I was having trouble getting p values to agree for two different methods. Thanks to a suggestion from a reader, there is a resolution: The p values should not agree. This was actually my hunch and hope a...

Animated choropleths to visualize mortality rates of children under 5 and gender differences using rMaps

September 17, 2014
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This post displays two animated choropleths. One for global mortality rates for children under 5 (per 1000 live births) and the second for the difference in global mortality rates for males and female children under 5 (per 1000). Please click here:&nbs...

BCEA 2.1

September 17, 2014
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We're about to release the new version of BCEA, which will contain some major changes.A couple of changes in the basic code that should improve the computational speed. In general, BCEA doesn't really run into troubles because most of the computations ...

Sampling distribution of maximum lilkelihood estimate – help?

September 17, 2014
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I'm doing Monte Carlo simulation of sampling distributions to compute p values. For example, consider the slope parameter, β1, in simple linear regression. I want to find out if p < .05 for a null hypothesis that β1=0. I'm working with two differe...

An open letter to Scotland on the eve of their independence vote

September 17, 2014
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Bye.

What do you do to visualize uncertainty?

September 17, 2014
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Howard Wainer writes: What do you do to visualize uncertainty? Do you only use static methods (e.g. error bounds)? Or do you also make use of dynamic means (e.g. have the display vary over time proportional to the error, so you don’t know exactly where the top of the bar is, since it moves while […]

Using great circles and ggplot2 to map arrival/departure of 2014 US Open Tennis Players

September 17, 2014
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Please click on the image for information on how to use R and ggplot2 to generate this plot.