Analyzing the 2015 California Health Interview Survey in R

A few years ago, I wrote about how to analyze the 2012 California Health Interview Survey in R. In 2012, plans for Covered California (Obamacare in California) were just beginning to take shape. Today, Covered California is a relatively mature program and it is arguably the most successful implementation of the Affordable Care Act in… Read More Analyzing the 2015 California Health Interview Survey in R

Analyzing the 2011-2012 California Health Inteview Survey with R

The California Health Interview Survey (CHIS) is a remarkable biannual survey of health status, care access, and demographics for California residents. The 2011-2012 public use survey data has recently been released and is freely available after registering at the CHIS site. CHIS currently offers data in SAS, Stata, and SPSS formats. However, thanks to a… Read More Analyzing the 2011-2012 California Health Inteview Survey with R

Going viral with R’s igraph package

R’s igraph package provides a simple and flexible set of utilities for working with graphs.  In this post, we’ll use this package to animate the simulated spread of a disease through a network. Graphs A graph is just a collection of nodes joined by edges:

In graph models, the nodes of a graph typically… Read More Going viral with R’s igraph package

Solving Quadratic Progams with R’s quadprog package

In this post, we’ll explore a special type of nonlinear constrained optimization problems called quadratic programs. Quadratic programs appear in many practical applications, including portfolio optimization and in solving support vector machine (SVM) classification problems. There are several packages available to solve quadratic programs in R. Here, we’ll work with the quadprog package. Before we… Read More Solving Quadratic Progams with R’s quadprog package