GUIs for R

March 28, 2011
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A recent post listed at R Bloggers (http://www.r-bloggers.com/r-guis-which-one-fits-you/) made some erroneous statements about R Commander. Here is a revised description of R Commander with some issues addressed from the earlier blog:R Commander works ...

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GUIs for R

March 28, 2011
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A recent post listed at R Bloggers (http://www.r-bloggers.com/r-guis-which-one-fits-you/) made some erroneous statements about R Commander. Here is a revised description of R Commander with some issues addressed from the earlier blog:R Commander works ...

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A Lattice Panel Function for Filled Polygons that Accounts for Missing Data

March 28, 2011
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A Lattice Panel Function for Filled Polygons that Accounts for Missing Data

This is a quick update to some code posted while back, related to plotting filled polygons within a lattice panel function. After attempting to use the originally described function to plot data with NA, I quickly realized that a more robust approach w...

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R Tutorial Series: 2011 ANOVA Article Data

March 28, 2011
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R Tutorial Series: 2011 ANOVA Article Data

Having wrapped up a recent flurry of R ANOVA articles (and exhausted my knowledge of the subject), I decided to take a look at the R Tutorial Series' Google Analytics data from the past few months. Since I posted the Two-Way Omnibus ANOVA article on J...

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R Tutorial Series: 2011 ANOVA Article Data

March 28, 2011
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R Tutorial Series: 2011 ANOVA Article Data

Having wrapped up a recent flurry of R ANOVA articles (and exhausted my knowledge of the subject), I decided to take a look at the R Tutorial Series' Google Analytics data from the past few months. Since I posted the Two-Way Omnibus ANOVA article on J...

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The devil of overfitting

March 27, 2011
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The devil of overfitting

Overfitting is a problem when trying to predict financial returns.  Perhaps you’ve heard that before.  Some simple examples should clarify what overfitting is — and may surprise you. Polynomials Let’s suppose that the true expected return over a period of time is described by a polynomial. We can easily do this in R.  The first … Continue reading...

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R-bloggers: I’m syndicated!

March 27, 2011
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Today Left Censored became a contributor to R-Bloggers. If you’ve never heard of it, R-Bloggers is a blog aggregator that brings together R-related posts from a large number of blogs across the Internet. It’s an excellent resource for those who … Continue reading →

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R [re-]exam

March 27, 2011
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R [re-]exam

In what seems like an endless cuRse, I found this week I had to re-grade a dozen R exams a TA’s did not grade properly! The grades I (X) got are plotted below against those of my TA (Y). There is little connection between both gradings… As if this was not enough trouble, I also

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R GUIs: Which one fits you?

March 27, 2011
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R GUIs: Which one fits you?

The gap of the new “digital divide” between those who only use computers when they are as easy to use as iPads and smartphones and those who like (or at least accept) to type commands to perform jobs, seems to get bigger and bigger. R – the lingua franca of statistical computing – is exactly

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R Matrix Operations

March 27, 2011
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R Matrix Operations

R can be used to perform various matrix calculations. This include functions for creating matrices (matrix), addition (+), multiplication (%*%) and inversion (solve). Fast Tube by Casper Other useful resources are provided on the Supplementary Material...

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More on Ultraedit to R

March 27, 2011
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I think I have found a superior solution to integrating Ultraedit and R. See my post over at IDM Users forum.

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R-ecap [-16]

March 26, 2011
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R-ecap [-16]

This morning, I noticed that none of my R related posts had appeared on R-bloggers for the past fortnight… After investigating, this was caused by…cut-and-paste! Indeed, when advertising about the special issue of TOMACS Arnaud Doucet and I edit about Monte Carlo methods in Statistics, I copied the main parts from the pdf announcement, straight

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clusterProfiler in Bioconductor 2.8

March 26, 2011
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In recently years, high-throughput experimental techniques such as microarray and mass spectrometry can identify many lists of genes and gene products. The most widely used strategy for high-throughput data analysis is to identify different gene clusters based on their expression profiles. Another commonly used approach is to annotate these genes to biological knowledge, such as Gene Ontology (GO) and...

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“An R package” or “A R package”

March 26, 2011
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“An R package” or “A R package”

I’m currently writing some lecture notes on R and I used the phrase “a R package” without thinking. Since the word following the article “a” was a consonant, I automatically went for “a” instead of “an”. The problem is that “R” sounds likes a vowel, so “a R package” grates on the listener. The correct

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solaR 0.22 is at CRAN

solaR 0.22 is at CRAN

The version 0.22 of solaR is now available at CRAN. Besides, solaR is now registered at R-Forge. A new mergesolaR method has been defined for merging solaR objects. The calculation of the sunset time has been improved. The voltage dependency of the efficiency curve of the inverter is now included in fProd and calcGCPV. The

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How to backtest a strategy in R

March 26, 2011
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This is the third post in the Backtesting in Excel and R series and it will show how to backtest a simple strategy in R.  It will follow the 4 steps Damian outlined in his post on how to backtest a simple strategy in Excel.Step 1: Get the dataThe ...

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How to backtest a strategy in R

March 26, 2011
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This is the third post in the Backtesting in Excel and R series and it will show how to backtest a simple strategy in R.  It will follow the 4 steps Damian outlined in his post on how to backtest a simple strategy in Excel.Step 1: Get the dataThe ...

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Le Monde puzzle [#7]

March 26, 2011
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Le Monde puzzle [#7]

The mathematical puzzle from the weekend edition of Le Monde from a few weeks ago was not too hard to solve by induction but my R code failed miserably! The puzzle was as follows: A calculator is broken in such a way that it starts by exhibiting 0, then pressing 4, 6 or 0 keeps

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A Request for Foursquare Data

March 25, 2011
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I’m trying to collect data sets that showcase how the classical statistical distributions appear in modern contexts. I’ve already got some data that shows how the gamma distribution appears in video game scores, and now I’m hoping to find an example where the exponential distribution

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Aquamacs 2.2 and ESS

March 25, 2011
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News of the latest release of Aquamacs, version 2.2, appeared this week in my echo area. Given the opportunity to procrastinate, I dropped everything and upgraded; returning to work, I noticed that the version of ESS shipped with Aquamacs 2.2 is ESS 5...

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R inside Qt: A simple RInside application

March 25, 2011
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R inside Qt: A simple RInside application

The RInside package makes it pretty simple and straightforward to embed R, the wonderful statistical programming environment and language, inside of a C++ application. This uses both the robust embedding API provided by R itself, and the higher-level...

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Because it’s Friday: Do Celebrities Follow the Half Your Age Plus Seven Rule?

March 25, 2011
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celeb small

Remember the Dating Equation from a while back, that formula that determines the socially acceptable bounds for the age of a female companion given the age of the male partner? Well, the crack data analysis team at Revolution Analytics decided to take the 100 hottest celebrity couples of 2010, and create a scatterplot of the couple's ages (using R),...

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Loading CSV with Date and Time into Zoo in R

March 25, 2011
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Sometimes you are facing time series which has both date and time property in one column in CSV file. In this case you need to pass additional parameter into read.zoo function:   View Code RSPLUS1 z <- read.zoo("/path/to/file/test.csv&...

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Grey’s Anatomy Network of Sexual Relations

March 25, 2011
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This all began with an introductory presentation about social network analysis to a group of medical students.  What better way to grab their attention than with attractive, fake doctors having sex on television?  Naturally this led to the dense network … Continue reading →

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MCMC with errors

March 25, 2011
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MCMC with errors

I received this email last week from Ian Langmore, a postdoc in Columbia: I’m looking for literature on a subject and can’t find it:  I have a Metropolis sampler where the acceptance probability is evaluated with some error.  This error is not simply error in evaluation of the target density.  It occurs due to the

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Day #11 Easter “egg”

March 25, 2011
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This is not my daily blogpost, but something I found while searching for different plots just copy this code and post it in your Rserve (or what you use to give in R commands) install.packages("onion") require(onion) data(bunny) p3d(bunny,theta=3,phi=1...

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Radiation levels at Fukushima

March 24, 2011
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Radiation levels at Fukushima

From BWR The above graph is derived from data scraped from TEPCO press releases. Every hour or so for the first few days of the crisis, a TEPCO van would record radiation (probably Beta/Gamma, but the translation is unclear) at … Continue reading →

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No simulation is complete without a gif

March 24, 2011
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No simulation is complete without a gif

I promise this is my last post on the now week and a half old π pay! Building on the last post, I figured I could show how convergence actually works in the estimation algorithm. If you’ll recall, we plotted … Continue reading →

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Predicting R models with PMML: Revolution R Enterprise and ADAPA

March 24, 2011
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The recently announced Revolution Analytics / Zementis partnership goes a long way towards demonstrating how R fits into big-league production environments. A frequent complaint against R is that although R is fine prototyping tool it is not able to handle production environments. Well, that’s just not true. In fact, it is straightforward to build a model in R, translate...

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