# Articles by Jason

### R and MPI on Ohio Supercomputer Center’s Oakley cluster

February 17, 2015 |

A few years ago, I wrote a short guide to Using R and snow on the Ohio Supercomputer Center’s Glenn cluster. Several things have changed in the world of R since then (namely, the inclusion of the parallel package into … Continue reading → [Read more...]

### Boolean 3 (finally) on CRAN

June 25, 2014 |

I have finally managed to get boolean3 accepted to CRAN. You can find it here: boolean3 on CRAN. To summarize: boolean3 provides a means of estimating partial-observability binary response models following boolean logic. boolean3 was developed by Jason W. Morgan under the … Continue reading → [Read more...]

### Pearson’s r: Not a good measure of electoral persistence

December 30, 2012 |

Pearson’s product-moment correlation, $$r$$, is an incredibly useful tool for getting some idea about how two variables are (linearly) related. But there are times when using Pearson’s $$r$$ is not appropriate and, even if linearity and all other assumptions hold, … Continue reading → [Read more...]

### R Tip: Avoid using T and F as synonyms for TRUE and FALSE

December 11, 2012 |

By default when you start R, T and F are defined as TRUE and FALSE. When I review other people’s code, I often see functions defined with arguments set to these values by default. This is a very bad idea. … Continue reading → [Read more...]

### Closures in R: A useful abstraction

December 2, 2012 |

People who have been using R for any length of time have probably become accustomed to passing functions as arguments to other functions. From my experience, however, people are much less likely to return functions from their own custom code. … Continue reading → [Read more...]

### Filtering a list with the Filter higher-order function

January 26, 2012 |

Last week markbulling over at Drunks & Lampposts posted a method of using sapply to filter a list by a predicate. Today the @RLangTip tip of the day was to use sapply similarly. This made makes me wonder if R‘s … Continue reading → [Read more...]

### Announcing boolean3 (beta)

January 24, 2012 |

After entirely too long, I am happy to announce the beta release of boolean3, an R package for modeling causal complexity. The package can be downloaded at the following links: Unix/Linux: boolean3_3.0.20.tar.gz Windows: boolean3_3.0.20.zip (Please let me know if you have any … Continue reading → [Read more...]

January 13, 2012 |

I have been working on a new package makeR to help manage Sweave projects where you wish to create multiple versions of documents that are based on a single source. For example, I create lots of monthly and quarterly reports using Sweave and the only differences between versions are a ... [Read more...]

### Visualizing Likert Items

November 11, 2011 |

I have become quite a big fan of graphics that combine the features of traditional figures (e.g. bar charts, histograms, etc.) with tables. That is, the combination of numerical results with a visual representation has been quite useful for exploring descriptive statistics. I have wrapped two of my favorites (... [Read more...]

### Managing a Local R Repository

November 10, 2011 |

I will be teaching a workshop on R and LaTeX at NEAIR in just under a month. One of the issues I will encounter is a lack of Internet access. I also work with restricted data from NCES which requires the computer to be secured including no network access. As ... [Read more...]

### Three free books for better programming in R (and any other language)

September 19, 2011 |

Like many users and producers of R packages, I have never had any formal training in computer science. I’ve come to to the conclusion that this is a serious omission in a professional researcher’s training. Computer scientists and professional hackers … Continue reading → [Read more...]

### The performance cost of a for-loop, and some alternatives

August 21, 2011 |

I’ve recently been spending a lot of time running various simulations in R. Because I often use snow to perform simulations across several computers/cores, results typically come back in the form of a list object. Summarizing the results from a list … Continue reading → [Read more...]

### Code: mtable-ext updated

June 21, 2011 |

I have fixed a small bug in mtable-ext that prevented asterisks from being printed for negative coefficients in mixed effects models output by lme4. Thanks to Reinhold Kliegl and Martin Elff for pointing out the bug and for providing the … Continue reading → [Read more...]

### A simple frequency plot

April 8, 2011 |

I’m currently working on a paper that uses Polish survey data (EVS 2008). I am specifically looking at regional variation in particular responses. Because there are only around 1800 observations in the survey, which are split across 66 subregions of … Continue reading → [Read more...]

### A very short and unoriginal introduction to snow

April 2, 2011 |

As ﻿Jian-Feng rightly pointed out in a comment on my guide to setting up snow on the OSC cluster, it was probably somewhat cavalier of me to say: Getting snow to run properly on single machines, or ever with a cluster of … Continue reading → [Read more...]

### Using R and snow on Ohio Supercomputer Center’s Glenn cluster

March 28, 2011 |

Over the last several days, I have had the “pleasure” of getting parallel processing with R running on the the Ohio Supercomputer Center’s (OSC) Glenn cluster. I am working on a project that uses GenMatch from Sekhon’s Matching, which uses … Continue reading → [Read more...]

### R-bloggers: I’m syndicated!

March 27, 2011 |

Today Left Censored became a contributor to R-Bloggers. If you’ve never heard of it, R-Bloggers is a blog aggregator that brings together R-related posts from a large number of blogs across the Internet. It’s an excellent resource for those who … Continue reading → [Read more...]

### Code: extended model support for mtable

March 22, 2011 |

I finally got around to organizing and packaging my complete set of extended model support for mtable in Martin Elff’s memisc library. Here is a list of the models supported: coxph, survreg – Cox proportional hazards models and parametric survival … Continue reading → [Read more...]

### data.table: an R package everyone should use

March 22, 2011 |

I’m not sure how I missed this package, but I am sure glad I’ve found it. The data.table package for R provides something of a reconceptualization of the standard data.frame object. Though it remains (mostly) compatible with data.frame. The advantage … Continue reading → [Read more...]

### Code: LaTeX tables for lme4 models

March 13, 2011 |

I have recently discovered memisc, an extremely useful R package by Martin Elff (see his memisc page here). The package contains any number of useful functions, and is particularly good at helping one manage and recode survey data. However, by far my … Continue reading → [Read more...]
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