Note: What other facts about Jeff Leek do you “know”? Please feel free to click the edit button above and submit a pull request on Github. I have not written blog posts for quite a while. It is not because I don’t have anything to write. On the contrary, ... [Read more...]

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The riddle of this week is about an optimisation of positioning the four digits of a multiplication of two numbers with two digits each and is open to a coding resolution: Four digits are drawn without replacement from {0,1,…,9}, one at a time. What is the optimal strategy to position those ... [Read more...]

The more common approach to QR decomposition is employing Householder reflections rather than utilizing Gram-Schmidt. In practice, the Gram-Schmidt procedure is not recommended as it can lead to cancellation that causes inaccuracy of the computation of , which may result in a non-orthogonal matrix. Householder reflections are another method of... The ... [Read more...]

by Andrie de Vries In 2014 we introduced the checkpoint package for reproducible research. This package makes it easy to use R package versions that existed on CRAN at a given date in the past, and to use varying package versions with different projects. Previous blog posts include: Introducing the Reproducible ... [Read more...]

Uncertainty is the biggest enemy of a profitable business. That is especially true of small business who don’t have enough resources to survive an unexpected diminution of revenue or to capitalize on a sudden increase of the demand. In this context, it is especially important to be able to ... [Read more...]

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I recently released an (other one) R package on CRAN - fuzzywuzzyR - which ports the fuzzywuzzy python library in R. “fuzzywuzzy does fuzzy string matching by using the Levenshtein Distance to calculate the differences between sequences (of... [Read more...]

We know that the NY Times data visualizations are pretty awesome, but the Wall Street Journal’s data visualizations are nothing to laugh at. In fact, one of my favorite books on data visualization is by Dona Wong, the former graphics editor of Wall Street Journal and a student of ... [Read more...]

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This coming Wednesday, April 19 at 8AM Pacific Time (click for your local time), Microsoft will be hosting a major on-line event of interest to anyone working with big data, analytics, and artificial intelligence: Microsoft Data Amp. During Data Amp, Executive Vice President Scott Guthrie and Corporate Vice President Joseph Sirosh ... [Read more...]

At the Ratemaking and Product Management (RPM) seminar of the Casualty Actuarial Society (CAS) in San Diego last month, Linda Brobeck, Peggy Brinkmann, and yours truly gave a concurrent session on a machine learning technique called decision tree analysis. See the DSPA-2 session -- and other sessions -- at this ... [Read more...]

Hello, R users! Today we're launching Beginning Bayes in R by Jim Albert. There are two schools of thought in the world of statistics, the frequentist perspective and the Bayesian perspective. At the core of the Bayesian perspective is the idea of rep... [Read more...]

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In the Exercises we will cover Hashes, Factors and Zoo in R Answers to the exercises are available here. Exercise 1 Create a Hash based Key Value Pairs with three employees, with Employees as the key and the name as the values. Exercise 2 Create Hash of an Employee with the Name, ... [Read more...]

There are two schools of thought in the world of statistics, the frequentist perspective and the Bayesian perspective. At the core of the Bayesian perspective is the idea of representing your beliefs about something using the language of probability, c... [Read more...]

This periodic table can serve as a guide to navigate the key players in the data science space. The resources in the table were chosen by looking at surveys taken from data science users, such as the 2016 Data Science Salary Survey by O'Reilly, the 201... [Read more...]

This periodic table can serve as a guide to navigate the key players in the data science space. The resources in the table were chosen by looking at surveys taken from data science users, such as the 2016 Data Science Salary Survey by O'Reilly, the... [Read more...]