Blog Archives

Version 1.0 of multilevelPSA Available on CRAN

February 14, 2013
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Version 1.0 of multilevelPSA Available on CRAN

Version 1.0 of multilevelPSA has been released to CRAN. The multilevelPSA package provides functions to estimate and visualize propensity score models with multilevel, or clustered, data. The graphics are an extension of PSAgraphics package by Helmreich and Pruzek. The example below will investigate the differences between private and public school internationally using the Programme of International Student Assessment...

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Converting a list to a data frame

January 30, 2013
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There are many situations in R where you have a list of vectors that you need to convert to a data.frame. This question has been addressed over at StackOverflow and it turns out there are many different approaches to completing this task. Since I encounter this situation relatively frequently, I wanted my own S3 method for as.data.frame that...

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Converting a list to a data frame

January 30, 2013
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There are many situations in R where you have a list of vectors that you need to convert to a data.frame. This question has been addressed over at StackOverflow and it turns out there are many different approaches to completing this task. Since I encou...

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Comparing two data frames with different number of rows

January 24, 2013
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I posted a question over on StackOverflow on an efficient way of comparing two data frames with the same column structure, but with different rows. What I would like to end up with is an n x m logical matrix where n and m are the number of rows in the first and second data frames, respectively; and...

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Version 1.0 of sqlutils available on CRAN

January 15, 2013
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Version 1.0 of sqlutils has been released to CRAN. The sqlutils package is designed to manage a library of SQL files. This package grew out of the needs of an Office of Institutional Research where the vast majority of analysis is conducted on data from our Student Information System (SIS) which is stored in an Oracle database. A lot...

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Interactive SQL in R

January 12, 2013
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Interactive SQL in R

I recently taught a very basic introduction to SQL workshop and needed a way to have participants interact with SQL statements. Obviously there are lots of tools to interface with a database, but since we are all R users I thought it would be nice to be able interact without leaving R. Although this interface is fairly basic, the...

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Reading Codebook Files in R

January 10, 2013
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One issue I continuously encounter when starting to work with a new dataset is that of the codebook. In general, I prefer to load a codebook into R like any other data source, specifically as a data frame. And ideally, one data frame to provides the variable names with descriptions and any other meta data available, and a separate...

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Function for Generating LaTeX Tables with Decimal Aligned Numbers

January 4, 2013
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Function for Generating LaTeX Tables with Decimal Aligned Numbers

The xtable package is tremendously useful for generating LaTeX tables from data frames. It is also pretty easy to customize the output to handle some special cases of LaTeX formatting. The xtable.decimal function will create a LaTeX table where numeric columns will be vertically aligned on the decimal point. In addition to specifying the LaTeX alignment code it...

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Using (R) Markdown, Jekyll, & GitHub for a Website

December 10, 2012
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IntroductionMarkdown has been growing in popularity for writing documents on the web. With the introduction of R Markdown (see also Jeromy Anglim’s post on getting started with R Markdown) and knitr, R Markdown has simplified the publishing of R analysis on the web. I recently converted my website from Wordpress to Jekyll. Jekyll...

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Fifty Shades of Grey in R

December 8, 2012
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Fifty Shades of Grey in R

My wife went out to her book group tonight and their book of the month was 50 Shades of Grey. Sadly, I could think of is that plotting 50 shades in R would be a neat exercise.require(ggplot2) grey50 <- data.frame( x = rep(1:10, 5), y = rep(1:5, ...

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