I have received a number of requests for demonstration code on how to perform a power analysis using simulation in R.  I have already demonstrated howto do this in Stata but lacked the easy to use Stata command “simulate” that I preferred.  However, in a recent post I have written ... [Read more...]

If you are anything like me then you have dozens if not hundreds of personal functions that you have written to accomplish a number of tasks.  Many of the tasks that you would like to do are similar to previous tasks that you have already done. &n... [Read more...]

I often want to simulate outcomes varying across a set of parameters. In order to accomplish this in an efficient manner I have coded up a little function that takes parameter vectors and produces results. First I will show how to set it up with some d... [Read more...]

I have programmed up a R based Sudoku problem solver for Sudoku puzzles of that only require simple inference.  In these puzzles a solution can be found using only first order inference.  This solver can be found at the end of the code locate... [Read more...]

# A single price monopolist is a monopolist because it is the only supplier of a particular product. The monopolist therefore has the power to choose a price to sell the product at. # Those who have a willingness to pay which is greater than the ... [Read more...]

This test is the first attempt to seriously assess the ability of individuals to survive a zombie apocalypse.  This test is administered using the R powered open-source testing platform Concerto developed at the University of Cambridge. The t... [Read more...]

On a recent flight I was bored waiting for the plane to land and I tried out the electronic sudoku game that they had offered.  I found the game surprisingly interesting as I realized that it is far more entertaining when you cannot use paper or p... [Read more...]

I have continued to explore the functionality of the Shiny package released by the Rstudio team and I have been increasingly impressed.  The code fits together very clean and easy to manipulate or add to.  If you have some knowledge of html o... [Read more...]

# There are several domain name servers that allow # for bulk searching of domain names.# http://www.godaddy.com/bulk-domain-search.aspx# http://www.namestation.com/bulk-domain-search# However, they do not provide any wildcard support # and instead exp... [Read more...]

I am not sure how many of you have seen this Business Insider article.  It is basically about a shiny app created by Joshua Katz as NC State.  It is really fun playing with shiny app.With nearly a million facebook likes this web app buil... [Read more...]

I have written a little function that allows users to run R scripts out of Dropbox directly from any location.  It was aided by this post on biobucket.  The reason I am particularly interested in this feature is because I am often using a ser... [Read more...]

Especially after the outcome of the mid-term election, I think there is a common contention among some groups that there is something wonky about Fox News when it comes to reporting polls relative to President Obama and the Democratic Party in general.... [Read more...]

Here is the code for my first Shiny App! It is the one that I posted previously with a few slight revisions. You can see it at:A Shiny R AppIn order to make any sense of this I suggest you working through the tutorial (http://www.rstudio.com/shiny/) ... [Read more...]

So I have finally gotten beta access to the two most powerful R controlled web application makers in existence and produced very exciting experimental productsA few posts ago I posted a Visual Reasoning Test that I had made by hand and powered wit... [Read more...]

# As a homage to Yitang Zhang who has proven a mind-bending property of Prime Pairs, I have written a prime Sieve to detect all of the prime numbers from 1 to N. # There might very well be a function in the base package that already does this. No... [Read more...]

I have just released my first complete test of non-verbal problem solving skills.  It is run on Concerto (an R-based application development platform targeted at primarily test developers)  Try it out by following the link below.Non-Verbal Re... [Read more...]

# Escape Zombie Land! # This is a simulation an escape from a hot zombie zone. It freezes and gives an error if you get get killed so you had best not. You attempt to navigate the zone by constructing waypoints. # This is not a very clean s... [Read more...]

# The SIR Model (susceptible, infected, and recovered) model is a common and useful tool in epidemiological modelling.# In this post and in future posts I hope to explore how this basic model can be enriched by including different population group... [Read more...]

# I am interested in how small bits of individualized instructions can create collective action.# In this simulation I will give a single instruction to each individual in the swarm.# Choose another individual who is not too close, then accelerate towards that individual.# I also control momentum causing the previous movement ... [Read more...]

[Read more...]