Or fancy words that mean very simple things. At the heart of most data mining, we are trying to represent complex things in a simple way. The simpler you can explain the phenomenon, the better you understand. It’s a little zen – compression is the same as understanding. Warning: Some ...

Oh, can it be, the voices calling me, they get lost and out of time (Little Black Submarines, The Black Keys) Last October I did this experiment about complex domain coloring. Since I like giving my posts a touch of randomness, I have done this experiment. I plot four random ...

R 3.1.3 (codename “Smooth Sidewalk”) was released today. You can get the latest binaries version from here. (or the .tar.gz source code from here). The full list of new features and bug fixes is provided below. Upgrading to R 3.1.3 on Windows If you are using Windows you can easily upgrade ...

Trying to clear my head of code on a dog walk after a couple of days tinkering with the nomis API and I started to ponder what an API is good for. Chris Gutteridge and Alex Duttion’s open data excuses bingo card and Owen Boswarva’s Open Data Publishing ...

This post will introduce my up and coming IKReporting package, and functions that compute and plot rolling returns, which are … Continue reading →

Introduction The topic in this post is endogeneity, which can severely bias regression estimates. I will specifically simulate endogeneity caused by an omitted variable. In future posts in this series, I’ll simulate other specification issues such as heteroskedasticity, multicollinearity, and collider bias. The Data-Generating Process Consider the data-generating process (...

Introduction This is the first post in a series devoted to explaining basic econometric concepts using R simulations. The topic in this post is endogeneity, which can severely bias regression estimates. I will specifically simulate endogeneity caused by an omitted variable. In future posts in this series, I’ll simulate ...

This post is a follow up to my last post on quadratic programming facilities in R. A commenter pointed me to the ipoptr project which exposes an R interface to the COIN-OR optimization routine Ipopt. COIN-OR is a suite of optimization utilities implemented in C++ and supported by a back-end ...