Most R functions used in econometrics convert factor variables into a set of dummy/binary variables automatically. This is useful when estimating a linear model, saving the user from the laborious activity of manually including the dummy variables as regressors. However, what if you want to reshape your dataframe so ... [Read more...]

Today I ran into a double question that might be relevant to other R users: Why can’t I assign a dataframe row into a matrix row? And why won’t my function accept this dataframe row as an input argument? A … Continue reading → [Read more...]

Both R and Python have facilities where the coder can write a script which requests a user to input some information. In Python 2.6, the main function for this task is raw_input (in Python 3.0, it’s input()). In R, there are a series of functions that can be used to ... [Read more...]

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In the 2012 edition of the SAP Sybase Capital Markets Guide, Revolution Analytics' Senior Advisor for Products and Strategy (and former CEO) Norman Nie writes about the "Five Benefits of Big Analytics". (You can also read his article at Enterprise Innovation.) Norman makes the argument that while sampling and aggregation are ... [Read more...]

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The webinar team at Revolution Analytics has put together a great program over the next couple of months. With a mix of guest speakers and Revolution Analytics staff, this series will cover topics as diverse as Big Data with R and Hadoop, integrating R with MS Office, spatial statistics with ... [Read more...]

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Thanks to the lower-than-usual snowfall over most of the US this past winter, there's low risk of major flooding as the snow melts this Spring (for the first time in four years!). Nonetheless, being able to forecast river flood events is of critical importance to local emergency managers, water & electric ... [Read more...]

I want to highlight two great Visualization techniques I discovered by reading the fine blog from Timely Portfolio. First method is based on the lm System on Nikkei with New Chart. Let’s visualize Strategy’s Long/Short/Not Invested periods by highlighting the underlying (i.e. buy & hold) with ... [Read more...]

Registration has been open for a while, but I wanted to point out the pre-conference seminars. Registrations are strong this year, so if you’re interested you’ll need to sign up before they sell out. Register here… As you probably know by now, the fourth annual R/Finance conference ... [Read more...]

  Here’s a fun example of how you might use my data on Congressional bill length and complexity.  Imagine you want to understand the empirical distribution of Flesch-Kincaid reading level for Congressional bills and how this distribution is related to … Continue reading → [Read more...]

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Typically, regression models in empirical economic research suffer from at least one form of endogeneity bias. The classic example is economic returns to schooling, where researchers want to know how much increased levels of education affect income. Estimation using a simple linear model, regressing income on schooling, alongside a bunch ... [Read more...]

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Following the question on dinner table permutations on StackExchange (mathematics) and the reply that the right number was six, provided by hardmath, I was looking for a constructive solution how to build the resolvable 2-(20,5,1) covering. A few hours later. hardmath again came up with an answer, found in the ... [Read more...]

I’m trying to make a mobile version of R-GUI, here is one (trying with iPhone emulator), not so beautiful, but still work. Try at CloudStat Mobile. Below are the screenshots: Homepage Web-based R Console Statistical Apps Directory ( R Apps ) ... [Read more...]

Bob Muenchen has recently updated his report on the popularity of statistical software. With the updated analysis, we see that the R community remains as strong as ever: the number of contributed R packages continues its exponential growth rate, R maintains its dominance in online discussion, and has 20x the ... [Read more...]

Summary: A new function in the WRS package compares many quantiles of two distributions simultaneously while controlling the overall alpha error. When comparing data from two groups, approximately 99.6% of all psychological research compares the central tendency (that is a … Continue reading → [Read more...]