Blog Archives

Results of an Informal Survey of R users

November 22, 2013
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Results of an Informal Survey of R users

# This post does some basic correlation analysis between responses# to the survey I recently released through R Shiny at:http://www.econometricsbysimulation.com/2013/11/Shiny-Survey-Tool.html # I have saved the data from the survey after completin...

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A Survey Tool Designed Entirely in Shiny Surveying Users of R

November 19, 2013
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A Survey Tool Designed Entirely in Shiny Surveying Users of R

I have written a very basic survey tool built entirely in the Shiny package of R.  I hope the tool is useful.  Modifying the survey for your own purposes is trivially easy (I hope).I have not commented my code so it is pretty messy right now....

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Alpha testing shinyapps.io – first impressions

November 17, 2013
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Alpha testing shinyapps.io – first impressions

ShinyApps.io is a new server which is currently in alpha testing to host Shiny applications.  It is being designed by the RStudio team and provides some distinct features different from that of the ShinyApps.io is intended for larger applications ...

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A Shiny App for Experimenting with Dynamic Programming

November 15, 2013
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A Shiny App for Experimenting with Dynamic Programming

This post demonstrates the dynamics involved in a susceptible, infected, and recovering (SIR) model previous post for the model.  The shiny ui and server code can be found on GitHub.of dynamic programming. As a dynamic infection model, I find it p...

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A Shiny App for Playing with OLS

November 11, 2013
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A Shiny App for Playing with OLS

Ordinary least squares continues to be the staple estimator for causal inference for good reason.  In order to help new and veteran OLS users get a better sense of how it is working I have created a shiny app that allows for instant interactivity ...

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The Motivation for the Poisson Distribution

November 4, 2013
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# The Poisson distribution has the interesting property that it# models outcomes from events that are independent and equally# likely to occur. The distribution takes only one parameter mu# which is equal to both the mean (expected number of events) #...

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Consumer’s Choosing an Optimal Bundle – Utility Maximization

November 2, 2013
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Consumer’s Choosing an Optimal Bundle – Utility Maximization

# The theoretical basis of classical consumer theory lies# in utility maximization. The idea is that consumers# make consumption decisions based on choosing a bundle # of goods that will maximize individual utility.# Despite this hypothesis being large...

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Efficiency Balanced Information Criterion for Item Selection

November 1, 2013
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Efficiency Balanced Information Criterion for Item Selection

# Han (2012) in the paper "An Efficiency Balanced Information Criterion # for Item Selection in Computerized Adaptive Testing" proposes a method# of evaluating potential items based on expected item potential information # as a function of maximum pote...

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A Call for Contributors

October 29, 2013
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Dear Readers,This blog has been going for a year and a half now and I have posted nearly 300 posts to date.  I plan to continue to post though I am going to probably continue to shift my focus from daily blogging to that of getting a dissertation ...

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Modified Bin and Union Method for Item Pool Design

October 28, 2013
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Modified Bin and Union Method for Item Pool Design

# Reckase (2003) proposes a method for designing an item pool for a computer# adaptive test that has been known as the bin and union method. This method# involves drawing a subject from a distribution of abilities. Then selecting# the item that maximi...

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