Exploring US Healthcare data

April 13, 2014
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Exploring US Healthcare data

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Following open courseware

April 13, 2014
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I love massive open online courses such as provided on Coursera and edX. So I enrolled in the Data Analysis for Genomics course on edX. I am not alone there as seen from this posting on FreshBiostats.I was shocked when I took the Pre-Course R self-asse...

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What’s Gained from Calculating Bayesian Probabilities?

April 12, 2014
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The previous post claimed it’s reasonable to expect frequencies in binary experiments to be near .5 simply because that’s what most possible outcomes lead to. Reasonable or not, there’s no guarantee it’ll happen however. If 1% o...

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“If you are primarily motivated to make money, you . . . certainly don’t want to let people know how confused you are by something, or how shallow your knowledge is in certain areas. You want to project an image of mastery and omniscience.”

April 12, 2014
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“If you are primarily motivated to make money, you . . . certainly don’t want to let people know how confused you are by something, or how shallow your knowledge is in certain areas. You want to project an image of mastery and omniscience.”

A reader writes in: This op-ed made me think of one your recent posts. Money quote: If you are primarily motivated to make money, you just need to get as much information as you need to do your job. You don’t have time for deep dives into abstract matters. You certainly don’t want to let […] The post “If you are primarily motivated to make money, you . . .…

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Think X, Y and Z: What’s in the pipeline?

April 12, 2014
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Think X, Y and Z: What’s in the pipeline?

Greetings from PyCon 2014 in Montreal!  I did a book signing yesterday at the O'Reilly Media booth.  I had the pleasure of working side by side with David Beazley, who was signing copies of The Python Cookbook, now updated for Python 3 and, I...

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“Murder or Coincidence?” Statistical Error in Court: Richard Gill (TEDx video)

April 12, 2014
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“Murder or Coincidence?” Statistical Error in Court: Richard Gill (TEDx video)

“There was a vain and ambitious hospital director. A bad statistician. ..There were good medics and bad medics, good nurses and bad nurses, good cops and bad cops … Apparently, even some people in the Public Prosecution service found the witch hunt deeply disturbing.” This is how Richard Gill, statistician at Leiden University, describes a […]

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“Schools of statistical thoughts are sometimes jokingly likened to religions. This analogy is not perfect—unlike religions, statistical methods have no supernatural content and make essentially no demands on our personal lives. Looking at the comparison from the other direction, it is possible to be agnostic, atheistic, or simply live one’s life without religion, but it is not really possible to do statistics without some philosophy.”

April 12, 2014
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This bit is perhaps worth saying again, especially given the occasional trolling on the internet by people who disparage their ideological opponents by calling them “religious” . . . So here it is: Sometimes the choice of statistical philosophy is decided by convention or convenience. . . . In many settings, however, we have freedom […] The post “Schools of statistical thoughts are sometimes jokingly likened to religions. This analogy…

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Shape File Selfies in ggplot2

April 12, 2014
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Shape File Selfies in ggplot2

In this post you will learn how to: Create your own quasi-shape file Plot your homemade quasi-shape file in ggplot2 Add an external svg/ps graphic to a plot Change a grid grob's color and alpha *Note get simple .md version … Continue reading →

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Le Monde sans puzzle [& sans penguins]

April 12, 2014
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Le Monde sans puzzle [& sans penguins]

As the Le Monde mathematical puzzle of this week was a geometric one (the quadrangle ABCD is divided into two parts with the same area, &tc…) , with no clear R resolution, I chose to bypass it. In this April 3 issue, several items of interest: first, a report by Etienne Ghys on Yakov Sinaï’s […]

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“More research from the lunatic fringe”

April 11, 2014
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A linguist send me an email with the above title and a link to a paper, “The Effect of Language on Economic Behavior: Evidence from Savings Rates, Health Behaviors, and Retirement Assets,” by M. Keith Chen, which begins: Languages differ widely in the ways they encode time. I test the hypothesis that languages that grammatically […] The post “More research from the lunatic fringe” appeared first on Statistical Modeling, Causal…

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Talking shop about probability

April 11, 2014
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It strikes me that the media loves to talk about probability, a subject about which journalists are ill-trained to write. The latest example of this is Forbes' attempt to draw a lesson out of the Warren Buffett's gimmicky $1 billion NCAA pool. As we all learned, by the time the 25th match drew to a close, all 8.7 million entrants have gotten at least one winner wrong, thus there would…

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Side-by-Side Box Plots with Patterns From Data Sets Stacked by reshape2 and melt() in R

Side-by-Side Box Plots with Patterns From Data Sets Stacked by reshape2 and melt() in R

Introduction A while ago, one of my co-workers asked me to group box plots by plotting them side-by-side within each group, and he wanted to use patterns rather than colours to distinguish between the box plots within a group; the publication that will display his plots prints in black-and-white only.  I gladly investigated how to […]

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Proof of a Result About the "Adjusted" Coefficient of Determination

April 10, 2014
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Proof of a Result About the "Adjusted" Coefficient of Determination

In a post last year I discussed the conditions under which the "adjusted" coefficient of determination (RA2) will increase or decrease, when regressors are deleted from (added to) a regression model. Without going over the full discussion again, h...

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Law of small numbers, in action

April 10, 2014
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Law of small numbers, in action

Loyal reader John M. expressed dismay over Twitter about 538's excessive use of bubble charts. Here's the picture that pushed John over the edge: The associated article is here. The question on the table is motivated by the extraordinary performance...

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Take a look, it’s in a book: distribution of kindle e-book highlights

April 10, 2014
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Take a look, it’s in a book: distribution of kindle e-book highlights

If you've ever started a book and not finished it, it may comfort you to know that you are not alone. It's hard to get accurate estimates of the percentage books that are discontinued, but the rise of e-reading (and… Continue reading →

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Small multiples of lineplots > maps (ok, not always, but yes in this case)

April 10, 2014
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Small multiples of lineplots > maps (ok, not always, but yes in this case)

Kaiser Fung shares this graph from Ritchie King: Kaiser writes: What they did right: - Did not put the data on a map - Ordered the countries by the most recent data point rather than alphabetically - Scale labels are found only on outer edge of the chart area, rather than one set per panel […] The post Small multiples of lineplots > maps (ok, not always, but yes in…

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The #rOpenSci hackathon #ropenhack

April 10, 2014
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Editor's note: This is a guest post by Alyssa Frazee, a graduate student in the Biostatistics department at Johns Hopkins and a participant in the recent rOpenSci hackathon.  Last week, I took a break from my normal PhD student schedule … Continue reading →

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Some past talks

April 10, 2014
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For those who weren't able to attend my recent talks, a few have surfaced online. *** JMP put up the video of the webcast from last Friday with Alberto Cairo, a data visualization expert and author of The Functional Art. You can access it from here. This event is part of their Analytically Speaking series with recent guests such as David Hand and Michael Schrage. I also appear on this…

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Simple speech recognition in Python

April 10, 2014
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Simple speech recognition in Python

Sometime today, I got the idea to try to do automatic speech recognition. Speech recognition, even though it is widely used (and is on our phones), still seems kind of sci-fi-ish to me. The thought of running it on your own computer is still pretty e...

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How to format decimals as fractions in SAS

April 10, 2014
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How to format decimals as fractions in SAS

Yesterday I blogged about the Hilbert matrix. The (i,j)th element of the Hilbert matrix has the value 1 / (i+j-1), which is the reciprocal of an integer. However, the printed Hilbert matrix did not look exactly like the formula because the elements print as finite-precision decimals. For example, the last […]

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Quick notes on file management in Python

April 10, 2014
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Quick notes on file management in Python

This is primarily for my recollection To expand ~ in a path name: To get the size of a directory:

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Machine Learning Lesson of the Day – Linear Gaussian Basis Function Models

Machine Learning Lesson of the Day – Linear Gaussian Basis Function Models

I recently introduced the use of linear basis function models for supervised learning problems that involve non-linear relationships between the predictors and the target.  A common type of basis function for such models is the Gaussian basis function.  This type of model uses the kernel of the normal (or Gaussian) probability density function (PDF) as […]

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Applied Statistics Lesson of the Day – Fractional Factorial Design and the Sparsity-of-Effects Principle

Applied Statistics Lesson of the Day – Fractional Factorial Design and the Sparsity-of-Effects Principle

Consider again an experiment that seeks to determine the causal relationships between  factors and the response, where .  Ideally, the sample size is large enough for a full factorial design to be used.  However, if the sample size is small and the number of possible treatments is large, then a fractional factorial design can be used instead.  Such a […]

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