Blog Archives

beepr (former pingr) is on CRAN. It’s easier than ever to make R go beep!

June 30, 2014
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beepr (former pingr) is on CRAN. It’s easier than ever to make R go beep!

Even though I said it would never happen, my silly package with the sole purpose of playing notification sounds is now on CRAN. Big thanks to the CRAN maintainers for their patience! For instant gratification run the following in R to install beepr and make R produce a notification sound: install.packages("beepr") library(beepr) beep() This package was previously called pingr and included...

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Bayesian First Aid: Test of Proportions

June 26, 2014
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Bayesian First Aid: Test of Proportions

Does pill A or pill B save the most lives? Which web design results in the most clicks? Which in vitro fertilization technique results in the largest number of happy babies? A lot of questions out there involves estimating the proportion or relative frequency of success of two or more groups (where success could be a saved life, a...

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The Most Comprehensive Review of Comic Books Teaching Statistics

June 11, 2014
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The Most Comprehensive Review of Comic Books Teaching Statistics

As I’m more or less an autodidact when it comes to statistics, I have a weak spot for books that try to introduce statistics in an accessible and pedagogical way. I have therefore collected what I believe are all books that introduces statistics using comics (at least those written in English). What follows are highly subjective reviews of those...

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Jeffreys’ Substitution Posterior for the Median: A Nice Trick to Non-parametrically Estimate the Median

May 3, 2014
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Jeffreys’ Substitution Posterior for the Median: A Nice Trick to Non-parametrically Estimate the Median

While reading up on quantile regression I found a really nice hack described in Bayesian Quantile Regression Methods (Lancaster & Jae Jun, 2010). It is called Jeffreys’ substitution posterior for the median, first described by Harold Jeffreys in his Theory of Probability, and is a non-parametric method for approximating the posterior of the median. What makes it...

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Bayesian First Aid: Pearson Correlation Test

March 17, 2014
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Bayesian First Aid: Pearson Correlation Test

Correlation does not imply causation, sure but, as Edward Tufte writes, “it sure is a hint.” The Pearson product-moment correlation coefficient is perhaps one of the most common ways of looking for such hints and this post describes the Bayesian First Aid alternative to the classical Pearson correlation test. Except for being based on Bayesian estimation (a good...

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A Hack to Create Matrices in R, Matlab style

March 7, 2014
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A Hack to Create Matrices in R, Matlab style

The Matlab syntax for creating matrices is pretty and convenient. Here is a 2x3 matrix in Matlab syntax where , marks a new column and ; marks a new row: Here is how to create the corresponding matrix in R: matrix(c(1,4,2,5,3,6), 2, 3) ## ## 1...

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Oldies but Goldies: Statistical Graphics Books

March 1, 2014
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Oldies but Goldies: Statistical Graphics Books

I just wanted to plug for three classical books on statistical graphics that I really enjoyed reading. The books are old (that is, older than me) but still relevant and together they give a sense of the development of exploratory graphics in general and the graphics system in R specifically as all three books were written at Bell Labs...

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Bayesian First Aid: Two Sample t-test

February 24, 2014
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Bayesian First Aid: Two Sample t-test

As spring follows winter once more here down in southern Sweden, the two sample t-test follows the one sample t-test. This is a continuation of the Bayesian First Aid alternative to the one sample t-test where I’ll introduce the two sample alternative. It will be a quite short post as the two sample alternative is just more of...

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A Significantly Improved Significance Test. Not!

February 12, 2014
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A Significantly Improved Significance Test. Not!

It is my great pleasure to share with you a breakthrough in statistical computing. There are many statistical tests: the t-test, the chi-squared test, the ANOVA, etc. I here present a new test, a test that answers the question researchers are most anxious to figure out, a test of significance, the significance test. While a test like the two...

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Bayesian First Aid: One Sample and Paired Samples t-test

February 4, 2014
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Bayesian First Aid: One Sample and Paired Samples t-test

Student’s t-test is a staple of statistical analysis. A quick search on Google Scholar for “t-test” results in 170,000 hits in 2013 alone. In comparison, “Bayesian” gives 130,000 hits while “box plot” results in only 12,500 hits. To be honest, if I had to choose I would most of the time prefer a notched boxplot to...

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