## When Does the Kinetic Theory of Gases Fail? Examining its Postulates with Assistance from Simple Linear Regression in R

$When Does the Kinetic Theory of Gases Fail? Examining its Postulates with Assistance from Simple Linear Regression in R$

Introduction The Ideal Gas Law, , is a very simple yet useful relationship that describes the behaviours of many gases pretty well in many situations.  It is “Ideal” because it makes some assumptions about gas particles that make the math and the physics easy to work with; in fact, the simplicity that arises from these

## Playing cards in Vegas?

May 19, 2013
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In a previous post, a few weeks ago, I mentioned that I will be in Las Vegas by the end of July. And I took the opportunity to write a post on roulette(s). Since some colleagues told me I should take some time to play poker there, I guess I have to understand how to play poker… so I...

## More tide prediction with R

May 19, 2013
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In the previous post I outlined how to query the XTide software with R and parse the results into a handy-dandy data frame. The biggest hurdle with that method is getting XTide up and running on your computer. The code outlined here works entirely within R, so you don’t need XTide installed on your computer.

## R code to obtain and plot rainfall data for the whole world

If you want to create rainfall maps for the whole world in R there is no readily available code or package to do this. Moreover, data publicly available from research institutions is not generally in plain text format or other familiar formats. Hydrological and climatological studies sometimes require rainfall data over the entire world for long periods of time....

## Exploratory Data Analysis – Computing Descriptive Statistics in R for Data on Ozone Pollution in New York City

Introduction This is the first of a series of posts on exploratory data analysis (EDA).  This post will calculate the common summary statistics of a univariate continuous data set – the data on ozone pollution in New York City that is part of the built-in “airquality” data set in R.  This is a particularly good data set

## Update to PSID panel builder for R: psidR

May 19, 2013
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I just pushed the most recent version of the PSID panel data builder introduced a little while ago. Got some user feedback and made some improvements. The package is hosted on github.News:I added a reproducible example using artificial data which you c...

May 18, 2013
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## Sharing my R notes

May 18, 2013
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I started working with R 2 1/2 years ago. I remember opening R closing it and thinking it was the dumbest thing ever (command line to a non programmer is not inviting). Now it’s my constant friend. From the beginning … Continue reading →

## Using gdata, for MS Windows users

May 18, 2013
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I use both GNU-Linux and Windows systems on a regular basis… so I’m aware of the advantages (more for GNU-Linux in my case) and disadvantages of both. Recently I needed to analyse a database from a remote location, an Excel … Sigue leyendo →

## R (Web Server) Solutions – Amplifying Artichokes

May 18, 2013
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Every month I see one or more new R based web server solutions coming into the market, sight seeing some of them thought of sharing one of my old architecture map manifested to the client long back in early 2009 (good to see quick spreading of scalable...

## What is probabilistic truth?

May 18, 2013
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I am currently working on a validation metric for binary prediction models. That is, models which make predictions about outcomes that can take on either of two possible states (eg Dead/not dead, heads/tails, cat in picture/no cat in picture, etc.) The most commonly used metric for this class of models is AUC, which assesses the

## Recent Changes to caret

May 18, 2013
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Here is a summary of some recent changes to caret. Feature Updates: train was updated to utilize recent changes in the gbm package that allow for boosting with three or more classes (via the multinomial distribution) The Yeo-Johnson power transformation was added. This is very similar to the Box-Cox transformation, but it does not require the data to be...

## Mining the last French presidential debate

May 18, 2013
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After reading this post (thanks to him), I think it could be interesting to replicate this with some specific up of french language and to see and we can perform rapid view of the debate between Sarkozy and Hollande of the last 2nd round of presidentia...

## Bubble sort tuning

May 18, 2013
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I was reading Paul Hiemsta's blogpost on Much more efficient bubble sort in R using the Rcpp and inline packages, went back to his first post  Bubble sort implemented in pure R and thought, surely we can do it better in pure R. So I...

## Interfacing XTide and R

May 17, 2013
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XTide is an open-source program that predicts tide heights and current speeds for hundreds of tide and current stations around the United States. It can be used to produce tide predictions in the past and future for a site at your chosen interval (down...

## Unit conversion in R

May 17, 2013
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Last weekend I submitted an update of my R package datamart to CRAN. It has been more than a half year since the last update, however there are only minor advances. The package is still in its early stages, and very experimental.One new feature is the function uconv. Think iconv, but instead of converting character vectors between different encodings,...

## Chutes & ladders: How long is this going to take?

May 17, 2013
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I was playing Chutes & Ladders with my four-year-old daughter yesterday, and I thought, “How long is this going to take?” I saw an interesting mathematical analysis of the game a few years ago, but it seems to be offline, though you can read it via the wayback machine. But that didn’t answer my specific

## Which Torontonians Want a Casino? Survey Analysis Part 2

May 17, 2013
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In my last post I said that I would try to investigate the question of who actually does want a casino, and whether place of residence is a factor in where they want the casino to be built.  So, here … Continue reading →

## R 3.0.1 released

May 17, 2013
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The R core group has quickly followed up with a patch to R version 3. Announced yesterday, R 3.0.1 (code name: "Good Sport") improves serialization performance with big objects, improves reliability for parallel programming and fixes a few minor bugs. (You can find the complete list of changes in the NEWS file.) The source distribution and Windows and Linux...

May 17, 2013
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The most recent edition of the Revolution Newsletter is out. The news section is below, and you can read the full May edition (with highlights from this blog and community events) online. You can subscribe to the Revolution Newsletter to get it monthly via email. Gaming Analytics FTW! Join us on 13Jun13 at 10:00 AM PDT for our webinar...

## Strategic Zombie Simulation – Animation

May 17, 2013
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# 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...

## Innovation Will Never Be At The Push Of A Button

May 17, 2013
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@randyzwitch @benjamingaines @usujason I am envisioning the data science equivalent of an autonomous vehicle pileup. — Todd Belcher (@toddmetrics) May 16, 2013   Recently, I’ve been getting my blood pressure up reading (marketing) articles about “big data” and “data science”.  What saddens me about the whole discussion is that there is the underlying premise that Innovation Will Never...

## Preferential attachment applied to frequency of accessing a variable

May 17, 2013
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If, when writing code for a function, up to the current point in the code distinct local variables have been accessed for reading times (), will the next read access be from a previously unread local variable and if not what is the likelihood of choosing each of the distinct variables (global variables are ignored

## Analyzing a simple experiment with heterogeneous variances using asreml, MCMCglmm and SAS

May 17, 2013
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I was working with a small experiment which includes families from two Eucalyptus species and thought it would be nice to code a first analysis using alternative approaches. The experiment is a randomized complete block design, with species as fixed effect and family and block as a random effects, while the response variable is growth

## Finding patterns in time series using regular expressions

May 17, 2013
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Regular expressions are a fantastic tool when you’re looking for patterns in time series. I wish I’d realised that sooner. Here’s a timely example: traditionally, when you have two successive quarters of negative GDP growth, you’re in recession. We have a quarterly GDP time series for Australia, and we want to know how many recessions

## Analyze More, Program Less: A Webinar about Using SciDB for Computational Finance

May 16, 2013
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Paradigm4 presents a webinar about using SciDB for scalable financial analytics. You’ll see how SciDB reaches Big Data scale without forcing you to become a computer scientist—no mapping, no reducing, no concocting parallel algorithms by hand. The webinar will also demonstrate SciDB-R, an R package that lets you remain an R programmer while enjoying the scalable

## Social Network Analysis at New Frontiers in Computing 2013

May 16, 2013
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by Joseph Rickert This past Saturday, the New Frontiers in Computing Conference (NFIC 2013), held at Stanford University, explored the theme: Social Network Analysis: It’s Who You Know. The speakers were a well-chosen, eclectic lot who covered a remarkable array of issues in less than a full day. Ian Hersey, former CTO of Attensity spoke on Lessons from Large-Scale...

## A function for comparing groups on a set of variables

May 16, 2013
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I'm often in the position of needing to compare groups of either items or participants on some set of variables. For example, I might want to compare recognition of words that differ on some measure of lexical neighborhood density but are matched on wo...

## Using RcppProgress to control the long computations in C++

May 16, 2013
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Usually you write c++ code with R when you want to speedup some calculations. Depending on the parameters, and especially during the development, it is difficult to anticipate the execution time of your computation, so that you do not know if you have to wait for 1 minute or hours. RcppProgress is a tool to help you monitor the...