Blog Archives

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

August 21, 2011
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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 →

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Code: mtable-ext updated

June 21, 2011
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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 →

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A simple frequency plot

April 8, 2011
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A simple frequency plot

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 →

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A very short and unoriginal introduction to snow

April 2, 2011
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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 →

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

March 28, 2011
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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 →

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R-bloggers: I’m syndicated!

March 27, 2011
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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 →

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Code: extended model support for mtable

March 22, 2011
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Code: extended model support for mtable

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 →

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Visualizing Missing Data

March 22, 2011
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Visualizing Missing Data

There are several graphics available for visualizing missing data. The following graphic was inspired by many sources. However, I wanted a version using ggplot2. What is visualized here is the percent missing for each variable in the PISA data across countries. The code will be available as part of the multilevelPSA package I am currently

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data.table: an R package everyone should use

March 22, 2011
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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 →

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Code: LaTeX tables for lme4 models

March 13, 2011
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Code: LaTeX tables for lme4 models

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 →

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