Where’s Waldo? Image Analysis in R

May 17, 2012
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Where’s Waldo? Image Analysis in R

R user Arthur Charpentier attempts to use the raster library and R functions to find Waldo in a "Where's Waldo" image: Sadly, it turned out that Waldo was a bit too tricky to spot using these techniques. But Arthur did have more success identifying the US flag in a shot from the Apollo mission, and identifying answers in the...

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Emulating local static variables in R

May 17, 2012
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Emulating local static variables in R

Recently I was writing a code allowing to plot multiple ggplot2 plots on one page. I wanted to replicate standard behavior of  plot  function that plots graphs in sequence according to  mfrow/ mfcol option in par...

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Orbitz: R has become the data-mining tool of choice

May 17, 2012
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Sameer Chopra, vice president of Advanced Analytics at Orbitz Worldwide, wrote recently in Analytics magazine about the changing landscape of processes, software and systems for statistical modelers. In a section on "Big Data and Open Source Analytics", Chopra lays out the reasons why the R language "has become the data-mining tool of choice for machine learners": R has very...

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Github Follower Graph with R

May 17, 2012
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Github Follower Graph with R

Graph a github user's followers (and follower's followers).Each programming language tends to develop its own idiomatic set of data structures.  In R, data frames are often the structure of choice.  JSON (a subset of Javascript) has emerged a...

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Excel Import into R without rJava

May 17, 2012
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In my ongoing quest to webappify various R scripts I discovered that rApache cannot load any R packages that depend on rJava.  For several of the scripts that I've written that grab data out of MS Excel files, and therein use the xlsx package, thi...

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More Bixi Data Visualization

May 17, 2012
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More Bixi Data Visualization

I mentioned in a previous post that our team at the recent Hack/Reduce hackathon had some fun with a data set which consisted of Bixi station states at minute level temporal resolution. In addition to pulling out and plotting the flux at each station on an hourly basis, we also plotted the system state (number

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Please Learn to Read

May 17, 2012
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There has been a lot of chatter during the past week on HN generated by with Jeff Atwood's "Please don't learn to code".  Actual posts included:Please don't learn to code (www.codinghorror.com) Please Don't Become Anything, Especially Not A P...

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Reproducible research with markdown, knitr and pandoc

May 17, 2012
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Reproducible research with markdown, knitr and pandoc

Over the last few weeks I was trying to optimise my workflow using markdow in combination with knitr and pandoc. Knitr is a grea new package by Yihui, expanding R’s capabilities for reproducible research. I will illustrate my work flow … Continue reading →

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R’s increasing popularity. Should we care?

May 17, 2012
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R’s increasing popularity. Should we care?

Some people will say ‘you have to learn R if you want to get a job doing statistics/data science’. I say bullshit, you have to learn statistics and learn to work in a variety of languages if you want to … Continue reading →

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Exponential decay models

May 17, 2012
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Exponential decay models

All models are wrong, some models are more wrong than others. The streetlight model Exponential decay models are quite common.  But why? One reason a model might be popular is that it contains a reasonable approximation to the mechanism that generates the data.  That is seriously unlikely in this case. When it is dark and … Continue reading...

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Sleep – Part I

May 16, 2012
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Sleep – Part I

Yes, that first night was incredibly rough, thanks for asking.

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Getting Started with R Markdown, knitr, and Rstudio 0.96

May 16, 2012
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Getting Started with R Markdown, knitr, and Rstudio 0.96

This post examines the features of R Markdown using knitr in Rstudio 0.96. This combination of tools provides an exciting improvement in usability for reproducible analysis. Specifically, this post (1) discusses getting started with R Markdown and knitr in Rstudio 0.96; (2) provides a basic example of producing console output and plots...

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Population of Iligan City from 1970 to 2010

May 16, 2012
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Population of Iligan City from 1970 to 2010

R Codeslibrary(ggplot2)library(grDevices)IliganCity <- c(104493, 118778, 167358, 226568, 273004, 285061, 308046, 322821)CensalYear <- c("1970", "1975", "1980", "1990", "1995", "2000", "2007", "2010")qplot(CensalYear, IliganCity, xlab = expression...

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An Example of Social Network Analysis with R using Package igraph

May 16, 2012
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An Example of Social Network Analysis with R using Package igraph

by Yanchang Zhao, RDataMining.com This post presents an example of social network analysis with R using package igraph. The data to analyze is Twitter text data of @RDataMining used in the example of Text Mining, and it can be downloaded … Continue reading →

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garch() uncertainty

May 16, 2012
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garch() uncertainty

As part of an on-going paper with Kerrie Mengersen and Pierre Pudlo, we are using a GARCH(1,1) model as a target. Thus, the model is of the form which is a somehow puzzling object: the latent (variance) part is deterministic and can be reconstructed exactly given the series and the parameters. However, estimation is not

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Update: Parameters as Population Quantities

May 16, 2012
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Some time ago, I had an ineloquent and less-than-cordial online discussion with a commenter on this site, partially about how statisticians define the term "parameter". This post is just to quote a relevant passage from "Bootstrap Methods and Their Application", by Davison and Hinkley (1997), that better articulates a point I had made earlier. 2.1.1

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Global Homicide Rates by Government Type

May 16, 2012
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Global Homicide Rates by Government Type

Surprising results For purposes of this article, any mention of homicide rates refers to reported homicide rates. Open vs Closed In mostly open countries (full democracies), the homicide rates are rather low when compared to other types of...

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My take on polar bar (a.k.a. consultant’s) charts

May 16, 2012
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My take on polar bar (a.k.a. consultant’s) charts

Once upon a time, when I was working at Johnson & Johnson (pharma branch), I was surrounded by a bunch of programmers working to develop (among other things) a nifty piece of software for internal use. Part of it was later released as freeware, cal...

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RProtoBuf 0.2.4

A new release 0.2.4 of RProtoBuf is now on CRAN. RProtoBuf provides GNU R bindings for the Google Protobuf data encoding library used and released by Google. This release once again contains a number of patches kindly contributed by Murray Stokely...

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Finding Waldo, a flag on the moon and multiple choice tests, with R

May 16, 2012
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Finding Waldo, a flag on the moon and multiple choice tests, with R

I have to admit, first, that finding Waldo has been a difficult task. And I did not succeed. Neither could I correctly spot his shirt (because actually, it was what I was looking for). You know, that red-and-white striped shirt. I guess it sho...

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Revolution Newsletter: May 2012

May 16, 2012
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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. New R Training Courses Announced. Three new R courses from leading R experts are...

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And the Winner is……

May 16, 2012
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R will overtake SAS and SPSS in 2015 - according to David Smith in his post on the Revolutions blog.I can believe that!© 2012, David E. Giles

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Stepping Outside My Open-Source Comfort Zone: A First Look at Golden Helix SVS

May 16, 2012
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Stepping Outside My Open-Source Comfort Zone: A First Look at Golden Helix SVS

I'm a huge supporter of the Free and Open Source Software movement. I've written more about R than anything else on this blog, all the code I post here is free and open-source, and a while back I invited you to steal this blog under a cc-by-sa license....

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Quickly Visualize Your Whole Dataset

May 16, 2012
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(This article was first published on W. Andrew Barr's Paleoecology Blog, and kindly contributed to R-bloggers) To leave a comment for the author, please follow the link and comment on his blog: W. Andrew Barr's Paleoecology Blog. R-bloggers.com offers daily e-mail updates about R news and tutorials on topics such as: visualization (ggplot2, Boxplots, maps, animation), programming (RStudio, Sweave,...

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Express Divorce in Mexico

May 16, 2012
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Express Divorce in Mexico

On October 2008 Mexico's capital, the Federal District, approved a version of no-fault divorce locally known as "express divorce". With the new law the requesting spouse no longer had to provide a cause to dissolve the marriage and the couple no longer had to live apart before filing for divorce. Furthermore, the process of...

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Submitting a package to CRAN

May 16, 2012
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The process is relatively smooth, I think - especially if you start off with a Linux machine. However, when I had to compile the package and documentation for BCEA, I still had a couple of blips. The first problem was in the documentation. R tries...

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Extending the sensory profiling data model

May 16, 2012
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Extending the sensory profiling data model

In this post I extend the multiplicative Bayesian sensory profiling model with effects for rounds and sessions. Is is not a difficult extension, but it brings the need for informative priors into the model. I do believe round and session effects exist,...

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Population of Tawi-Tawi from 1903 to 2010

May 16, 2012
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Population of Tawi-Tawi from 1903 to 2010

R Codeslibrary(ggplot2)library(colorRamps)TawiTawiPop <- c(17000, 45000, 46000, 59000, 79000, 110000, 143000, 195000, 228204, 250718, 322317, 450346, 366550)YearNames <- c("1903", "1918", "1939", "1948", "1960", "1970", "1975", "1...

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Dynamic Content with RStudio, Markdown, and Marked.

May 15, 2012
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Dynamic Content with RStudio, Markdown, and Marked.

As Markus Gesmann recently pointed out, the new version of RStudio (0.96) has some really nice features for creating dynamic reports with Yihui Xie’s knitr. You can integrate not just R and LaTeX, but also R and Markdown (as well as some other fo...

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