cheatR is a mini package to help you find cheaters by comparing hand-ins. It was developed by Almog Simchon and me in response to students overheard bragging about how an assignment in an first-year undergrad course was “super easy” because “we all just copied from each other!” (though this would ...

Our idea was to compare each hand-in to all other hand-ins and see the degree of overlap between them. This was achieved using the ngram r-package to break each hand-in into a list of “phrases” and then to count how many times each phrase appeared across a pair of documents1. ...

Approximately 144 new packages stuck to CRAN in June. That fact that 31 of these are specialized to particular scientific disciplines or analyses provides some evidence to my hypothesis that working scientists are actively adopting R. Below are my Top 40 picks for June, organized into the categories of Computational Methods, Data, Data ...

By Gabriel Vasconcelos In this previous post I discussed some of the parameters we have to tune to estimate a boosting model using the xgboost package. In this post I will discuss the two parameters that were left out in … Continue reading →

Finding the neural stem cell populations in mouse brain   Introduction The main objective of this project is to identify new stem cell populations in mouse brain. Characterizing the unique gene expression signature of these cells could be the starting point for finding and defining cancer stem cells (CSC) in human ...

A simple Le Monde mathematical puzzle none too geometric: Find square triangles which sides are all integers and which surface is its perimeter. Extend to non-square rectangles. No visible difficulty by virtue of Pythagore’s formula: for (a in 1:1e4) for (b in a:1e4) if (a*b==2*(a+b+...

Based on a paper published in JAMA last year, the weight gain is increasing among US adults while there is no difference in the percentage of people that were trying to lose weight. The authors used the data from the National Health and Nutrition Examination Survey NHANES from 1988 to 2014 and ...

When you think of R, defensive coding may not be your first thought. But writing code that fails well & is easy to debug is more important than you'd think. The post The Ten Rules of Defensive Programming in R appeared first on Doodling in Data.

MaxDiff is a type of best-worst scaling. Respondents are asked to compare all choices in a given set and pick their best and worse (or...

As noted elsewhere, sometimes beauty matters. A plot that’s pleasing to the eye will be considered more gladly, and thus might be understood more thoroughly. Also, since we at STATWORX oftentimes need to subsume and communicate our results, we have come to appreciate how a nice plot can upgrade ...

Introduction It is 35 degree Celsius out side, we are in the middle of the ‘slow news season’, in many countries also called cucumber time.  A period typified by the appearance of less informative and frivolous news in the media. … Continue reading →

Continuing the blog’s UDF theme of late, there are two new UDF kids in town: drill-url-tools🔗 for slicing & dicing URI/URLs (just going to use ‘URL’ from now on in the post) drill-domain-tools🔗 for slicing & dicing internet domain names (IDNs). Now, if you’re an Apache Drill fanatic, you’...

In an earlier post, I focused on an in depth visit with CHAID (Chi-square automatic interaction detection). Quoting myself, I said “As the name implies it is fundamentally based on the venerable Chi-square test – and while not the most powerful (in terms of detecting the smallest possible differences) or the ...