#R#

R Programming

Basic Programming

  Loops

  Matrix operations in R

  Symbolic Math - Differentiation in R

  assigns in R

  User written functions in R

  Making regex examples work for you!

Powertools

  3 Ways of Loading SPSS (sav) files into Stata

  Batch Convert files from SPSS into Stata format

  Draw n values from a defined set

  Program Your own Bootstrap Command #R#

  Easy Monte Carlo Sampler Command

  The Power of the Evaluate, Parse, Paste Combination

  A Command for Randomly Creating Sets of Elements from a Vector

Econometrics

Basic Statistics

  Power Analysis

  Power Analysis by Simulation: R, RCT, Malaria Example

  Computing Expected Values 

  The Motivation for the Poisson Distribution

  Maximum Likelihood Estimation and the Origin of Life

Economics

  Consumer's Choosing an Optimal Bundle - Utility Maximization

  Optimal Pricing for a Simple Monopolist

Baysian Estimation

  My First Bayesian (Markov Chain Monte Carlo) Simulation

Write Your Own Estimators

  Write your own System IV estimator in R (and SOLS)

Probability

  The Importance of Independence

  The DELTA method

  Calculate an Empirical CDF for a random variable

  Maximum Likelihood Using R

  Simulation of Blackjack: the odds are not with you

Random Walk

  A Visual Exploration of Two Dimensional Random Walks

Spatial Simulations

  Simulating Spatial Data

  Monster Mash - Spatial Multi-Agent Simulation

Meta-Analysis

  Meta-Analysis Simulation - Monte Carlo

Hierarchical Linear Modelling

  A simple simulation of HLM using two different R packages

Psychometrics

Simulating Individual Items

  Playing around with IRT Graphs

  Simulating 3 parameter IRT data

  Generalized Graded Response Model

  Polytomous Rasch Model (Generalized Partial Credit Model)

  Generalized Graded Response Data Generating Command
  Item Information - IRT

Generating Tests

  Generating Tests of Particular Properties

  Matching Test Information

  Modified Bin and Union Method for Item Pool Design

  Item Equating with same Group - SAT, ACT example

Item Response Theory Parameter Estimation

  Item Response Theory Estimation

  Maximum Likelihoods and Item Response Theory

  Estimating Person Characteristics from IRT Data - 3PL Model

Computer Adaptive Tests

  Selecting your First Item on a Computer Adaptive Test

  CAT using Kullback–Leibler vs Fisher Information

  Computer Adaptive Test Assuming an Infinite Item Pool

  the catR package for Computer Adaptive Test design

  Efficiency Balanced Information Criterion for Item Selection

Psychometrics' Metrics

  Estimating Reliaility

Web Apps 

Concerto - Test Construction 

  Concerto v4.b web-based Content Management System for R Users

  Concerto Simple Demonstration Test v4.b

  Non-verbal reasoning test - Concerto

  Zombie Apocalypse Survival Test - R-Powered (using Concerto) 

Concerto - Item Construction

  Non-Verbal Reasoning Test Construction Part 1-Shape Creation

Shiny

  More explorations of Shiny

  A Shiny App Goes Viral
  Running R Scripts Directly From Dropbox
  Item Analysis App - Shiny Code
  Shiny + Concerto = YES !!!

Miscellaneous

Artificial Intelligence
  A Sudoku Puzzle Solver - attempt 1
  Sudoku Automation Solver Challenge - R
  Bulk search for domain names using R
 
Unfiled
  Using Simulations to Maximize Stochastic Models
  Lorenz Attractor Simulation
  Explosive Roommate Combinations

  Optimal Presidential Seeking Behavior
  US Daily Gun Deaths R Animation - Sandy Hook
  Loading up your custom toolkits at startup - R

Social Networks
  Simulating Social Network Data
  Simulating Social Network Hotspots

R & Stata Bridge
  7 commands in R & Stata
  Nested functions in R and Stata
  Stata is to Accounting as R is to Tetris
  R vs Stata Non-linear least squares!
  ANOVAs and MANOVAs
  Rstylizer - Shiny, Stata HTML Syntax Highlighter
  Question and Answer: Generating Binary and Discrete Response Data
  A Stata HTML syntax highlighter in R

Dynamic Models
  SIR Model - The Flu Season - Dynamic Programming
  A Dynamic Simulation of a Zombie Apocalypse
  Tit for Tat - Axelrod tournament style competitive simulation

Graphics/Animations
  Creating an easy pie chart from data vectors
  Strategic Zombie Simulation
  Spatial Critter Swarming Simulation
  Generate GIP integrated animation: Gun deaths animation
  Doodling in R!
  Are Fox News Polls Biased?
  My Prime Sieve - Homage to Yitan Zhang
 
R-Tools
  Export R Results Tables to Excel - Please don't kick me out of your club
  dapply - tapply for dataframes