# coding tips

### How to Shade Under a Normal Density in R

April 3, 2011 |

The easiest-to-find method for shading under a normal density is to use the polygon() command. That link is to the first hit on Google for "Shading Under a Normal Curve in R." It works (like a charm), but it is not the most intuitive way to let users p...

### How to Bootstrap in R: The Case of R-squared

March 29, 2011 |

I recorded a new video tutorial whose original intent was to demonstrate how to write a for loop. As I wanted to make the for loop count for something, I decided that my application would be to write some code that computes the bootstrap approximation ...

### Basic Plots in R

March 7, 2011 |

Here's a tutorial I recorded on producing basic plots in R.I lost the script file I used to create the video to a horrifying black screen of death, but I used the data from the previous post (available here). Hopefully, the video is clear enough that ...

### Testing Multiple Linear Restrictions in R

March 3, 2011 |

This video shows a couple of things:1. How to test (multiple) linear restrictions in R.2. How to install a package in R. Here is the code I use in the video (with some extra comments).Here is the data set that I use in the video.

### How Does R Deal with Categorical Explanatory Variables?

March 1, 2011 |

Here's a video tutorial where I demonstrate an answer to this question.This video is designed to instill a baseline level of practical knowledge. There is more to how R treats factors in regression models. An interested reader should Google "R contra...

### Running a Regression in R

February 28, 2011 |

I created another video tutorial on R. This time, I discuss R's lm() command and how to use it for a variety of standard applications.Here is the code that goes with the video:Enjoy!