I struggled with whether or not I should even post this.  It is raw and ugly, but it might help somebody out there.   I might use this as a basis for some more gridSVG posts, but I do not think I have the motivation to finish the analysi... [Read more...]

For my research on the effect of power outages on fertility , we study a period of extensive power rationing that lasted for almost a whole year and affected most of Latin America, but in particular, it affected Colombia. The key difficult was to determine which areas were exposed to the ... [Read more...]

Following up on my previous post as a result of an excellent suggestion from Andrej Spiess. The data are indeed very heteroscedastic! Andrej suggested that an alternative way to attack this problem would be to use weighted correlation with weights being the inverse of the measurement variance. Let’s look ... [Read more...]

This post spawned from a discussion I had the other day. Confidence intervals are notoriously a difficult topic for those unfamiliar with statistics. I can’t really think of another statistical topic that is so widely published in newspaper articles, television, and elsewhere that so few people really understand. It’... [Read more...]

While preparing for the new teaching semester I have created an implementation of NetLogo GenDrift P local in GNU R.The model works as follows. Initially a square grid having side size is randomly populated with n types of agen... [Read more...]

Mango Solutions are pleased to announce a free R Graphics Workshop in Copenhagen on Monday 26th August (6-8pm). The workshop is open to all and any interested R users or [Read more...]

R lacks some of the more “utilitarian” features found in other scripting languages that were/are more geared—at least initially—towards systems administration. One of the most frustrating missing pieces for security data scientists is the lack of ability to perform basic IP address manipulations, including reverse DNS resolution (... [Read more...]

So I have been having difficulty getting my Stata code to look the way I want it to look when I post it to my blog.  To alleviate this condition I have written a html encoder in R.  I don't know much about html so it is likely to be ... [Read more...]

If you're an absolute beginner to the R language, this Intro to R video series from Google Developers is a great place to get started. Just download R for your system, start the playlist below, and follow along with the on-screen examples. (The video uses the MacOS X version of ... [Read more...]

Having been at the University of Kansas (Kansas Jayhawks) as a student and now working at Gonzaga University (Gonzaga Bulldogs), discussions about college basketball are inescapable. This post uses R, ggmap, ggplot2 and the shiny server to graphically ... [Read more...]

If you’re a regular reader of my blog you’ll know that I’ve spent some time dabbling with neural networks. As I explained here, I’ve used neural networks in my own research to develop inference into causation. Neural networks fall under two general categories that describe their ... [Read more...]

Introduction Continuing my recent series on exploratory data analysis (EDA), today’s post focuses on 5-number summaries, which were previously mentioned in the post on descriptive statistics in this series.  I will define and calculate the 5-number summary in 2 different ways that are commonly used in R.  (It turns out ... [Read more...]

Data mining techniques and algorithms such as Decision Tree, Naïve Bayes, Support Vector Machine, Random Forest, and Logistic Regression are “most commonly used for predicting a specific outcome such as response / no-response, high / medium / low-value customer, likely to buy / not buy.”1 In this article, we will demonstrate how to ... [Read more...]

In the last post on the changepoint package, I concluded with a brief example of time series decomposition with the "decompose" command.  After further reading, I discovered the "stl" command, which to me appears a superior method.  STL stand... [Read more...]

the national plan and provider enumeration system (nppes) contains information about every provider, insurance plan, and clearinghouse actively operating in the united states healthcare industry.  did i just see the ears of all the health workforce researchers in the room perk up?  it's freely downloadable, courtesy of the department of ... [Read more...]

A very busy spring has transitioned into a very busy summer, so let me recap a few topics that probably deserve more time than I’ll give them here. Here are the things I’m overdue on, in no particular order: Publications In the March edition of the Journal of ... [Read more...]

In the spirit of my first post (Pappu Vs. Feku) I will continue to explore the use of Twitter in providing an eye into the events of contemporary interest, and movies are certainly something that capture interest of a large majority of Indian audience. So I am looking at Chennai ... [Read more...]

In part one and part two of Modeling Match Results in La Liga Using a Hierarchical Bayesian Poisson Model I developed a model for the number of goals in football matches from five seasons of La Liga, the premier Spanish football league. I’m now reasonably happy with the model ... [Read more...]

I would never call myself a programmer, but as an ecologists I manage moderately big and complicated datasets, and that require to interact with my computer to get the most of them. I self-taught most of the things I need … Continue reading → [Read more...]

A week or so ago a colleague of mine asked if I knew how to calculate correlations for data with uncertainties. Now, if we are going to be honest, then all data should have some level of experimental or measurement error. However, I suspect that in the majority of cases ... [Read more...]