Bootstrap Evaluation of Clusters

September 4, 2015
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Bootstrap Evaluation of Clusters

Illustration from Project Gutenberg The goal of cluster analysis is to group the observations in the data into clusters such that every datum in a cluster is more similar to other datums in the same cluster than it is to datums in other clusters. This is an analysis method of choice when annotated training data … Continue reading Bootstrap Evaluation of Clusters

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"Reproducibility and Reliability in Statistical and Data Driven Research" (Week after Next at the Statistics Seminar)

September 4, 2015
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Attention conservation notice: Publicity for an upcoming academic talk, of interest only if (1) you will be in Pittsburgh and (2) you care about whether scientific research can be reproduced. The timeliness of the opening talk of this year's statisti...

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P-values and statistical practice

September 4, 2015
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What is a p-value in practice? The p-value is a measure of discrepancy of the fit of a model or “null hypothesis” H to data y. In theory the p-value is a continuous measure of evidence, but in practice it is typically trichotomized approximately into strong evidence, weak evidence, and no evidence (these can also […] The post P-values and statistical practice appeared first on Statistical Modeling, Causal Inference, and…

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Mathematical art (part 2): Unweaving matrices

September 4, 2015
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Mathematical art (part 2): Unweaving matrices

In my previous blog post, I showed how you can use SAS to program a "weaving" algorithm that takes an image, cuts it into strips, and weaves the strips together to create mathematical art. I used matrices and heat maps for the computations and visualization. At the end of the […] The post Mathematical art (part 2): Unweaving matrices appeared first on The DO Loop.

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ABC model choice via random forests [and no fire]

September 3, 2015
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ABC model choice via random forests [and no fire]

While my arXiv newspage today had a puzzling entry about modelling UFOs sightings in France, it also broadcast our revision of Reliable ABC model choice via random forests, version that we resubmitted today to Bioinformatics after a quite thorough upgrade, the most dramatic one being the realisation we could also approximate the posterior probability of […]

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ABC model choice via random forests [and no fire]

September 3, 2015
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ABC model choice via random forests [and no fire]

While my arXiv newspage today had a puzzling entry about modelling UFOs sightings in France, it also broadcast our revision of Reliable ABC model choice via random forests, version that we resubmitted today to Bioinformatics after a quite thorough upgrade, the most dramatic one being the realisation we could also approximate the posterior probability of […]

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A Psych Science reader-participation game: Name this blog post

September 3, 2015
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A Psych Science reader-participation game:  Name this blog post

In a discussion of yesterday’s post on studies that don’t replicate, Nick Brown did me the time-wasting disservice of pointing out a recent press release from Psychological Science which, as you might have heard, is “the highest ranked empirical journal in psychology.” The press release is called “Blue and Seeing Blue: Sadness May Impair Color […] The post A Psych Science reader-participation game: Name this blog post appeared first on…

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reaching transcendence for Gaussian mixtures

September 2, 2015
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reaching transcendence for Gaussian mixtures

“…likelihood inference is in a fundamental way more complicated than the classical method of moments.” Carlos Amendola, Mathias Drton, and Bernd Sturmfels arXived a paper this Friday on “maximum likelihood estimates for Gaussian mixtures are transcendental”. By which they mean that trying to solve the five likelihood equations for a two-component Gaussian mixture does not […]

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reaching transcendence for Gaussian mixtures

September 2, 2015
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reaching transcendence for Gaussian mixtures

“…likelihood inference is in a fundamental way more complicated than the classical method of moments.” Carlos Amendola, Mathias Drton, and Bernd Sturmfels arXived a paper this Friday on “maximum likelihood estimates for Gaussian mixtures are transcendental”. By which they mean that trying to solve the five likelihood equations for a two-component Gaussian mixture does not […]

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How do you know if your model is going to work? Part 1: The problem

September 2, 2015
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How do you know if your model is going to work? Part 1: The problem

Authors: John Mount (more articles) and Nina Zumel (more articles). “Essentially, all models are wrong, but some are useful.” George Box Here’s a caricature of a data science project: your company or client needs information (usually to make a decision). Your job is to build a model to predict that information. You fit a model, … Continue reading How do you know if your model is going to work? Part…

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USAs usannsynlige presidentkandidat.

September 2, 2015
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USAs usannsynlige presidentkandidat.

With current lag, this should really appear in September but I thought I better post it now in case it does not remain topical. It’s a news article by Linda May Kallestein, which begins as follows: Sosialisten Bernie Sanders: Kan en 73 år gammel jøde, født av polske innvandrere, vokst opp under enkle kår og […] The post USAs usannsynlige presidentkandidat. appeared first on Statistical Modeling, Causal Inference, and Social…

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To understand the replication crisis, imagine a world in which everything was published.

September 2, 2015
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To understand the replication crisis, imagine a world in which everything was published.

John Snow points me to this post by psychology researcher Lisa Feldman Barrett who reacted to the recent news on the non-replication of many psychology studies with a contrarian, upbeat take, entitled “Psychology Is Not in Crisis.” Here’s Barrett: An initiative called the Reproducibility Project at the University of Virginia recently reran 100 psychology experiments […] The post To understand the replication crisis, imagine a world in which everything was…

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A not-so-satisfying rose

September 2, 2015
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A not-so-satisfying rose

At the conference in Bavaria, Jay Emerson asked participants to provide comments on the data visualization of the 2014 Environmental Performance Index (link). We looked at the country profiles in particular. Here is one for Singapore: The main object of...

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Mathematical art: Weaving matrices

September 2, 2015
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Mathematical art: Weaving matrices

An artist friend of mine recently created a beautiful abstract image and described the process on her blog. She says that "after painting my initial square, I cut it into strips and split them down the middle, then wove them together.... I had no idea when I started piecing these […] The post Mathematical art: Weaving matrices appeared first on The DO Loop.

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Mathematical annotations on R plots

September 2, 2015
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Mathematical annotations on R plots

I’ve always struggled with using plotmath via the expression function in R for adding mathematical notation to axes or legends. For some reason, the most obvious way to write something never seems to work for me and I end up using trial and error in a loop with far too many iterations. So I am […]

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Encounters with HCI Pioneers

September 2, 2015
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Ben Shneiderman has put together a series of postings about the Pioneers of Human-Computer Interaction (HCI). Each includes a brief biography, some personal notes by Ben, as well as Ben’s photos of them. The latter are particularly remarkable, often going back to the 1980s – like the gem at the top of this page, showing … Continue reading Encounters with HCI Pioneers

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September Reading List

September 1, 2015
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September Reading List

Abeln, B. and J. P. A. M. Jacobs, 2015. Seasonal adjustment with and without revisions: A comparison of X-13ARIMA-SEATS and CAMPLET. CAMA Working Paper 25/2015, Crawford School of Public Policy, Australian National University.Chan, J. C. C. and A. L. G...

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Bayesian analysis of gluten sensitivity

September 1, 2015
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Bayesian analysis of gluten sensitivity

Last week a new study showed that many subjects diagnosed with non-celiac gluten sensitivity (NCGS) were not able to distinguish gluten flour from non-gluten flour in a blind challenge.In this article, I review the the study and use a simple Bayesian m...

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Ahead of their Time

September 1, 2015
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Ahead of their Time

A picture helps understanding facts  – and this since hundreds of years. Investintech presents a (very) short insight in the history of data visualisation. Playfair For visualisation of statistics, William Playfair is a very important pioneer. More about William Playfair in this blog post:      Filed under: 031 Data visualization Tagged: data, history, visualisation

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Ahead of their Time

September 1, 2015
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Ahead of their Time

A picture helps understanding facts  – and this since hundreds of years. Investintech presents a (very) short insight in the history of data visualisation. Playfair For visualisation of statistics, William Playfair is a very important pioneer. More about William Playfair in this blog post:      Filed under: 031 Data visualization Tagged: data, history, visualisation

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Stan attribution

September 1, 2015
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Stan attribution

I worry that I get too much credit for Stan. So let me clarify. I didn’t write Stan. Stan is written in C++, and I’ve never in my life written a line of C, or C+, or C++, or C+++, or C-, or any of these things. Here’s a quick description of what we’ve all […] The post Stan attribution appeared first on Statistical Modeling, Causal Inference, and Social Science.

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Books to Read While the Algae Grow in Your Fur, April 2015

September 1, 2015
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Attention conservation notice: I have no taste. Christian Caryl, Strange Rebels: 1979 and the Birth of the 21st Century A very nicely written popular history of five movements that either began or reached a peak in 1979: the Iranian Revolution, the...

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Bayesian regression models using Stan in R

September 1, 2015
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Bayesian regression models using Stan in R

It seems the summer is coming to end in London, so I shall take a final look at my ice cream data that I have been playing around with to predict sales statistics based on temperature for the last couple of weeks [1], [2], [3].Here I will use the new b...

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