Time series equivalence of brains and markets

September 27, 2011
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Time series equivalence of brains and markets

fMRI data from 90 locations in the brain look somewhat like daily closing prices on 116 stocks if you squint just right. Marginal Revolution was nice enough to point to “Topological isomorphisms of human brain and financial market networks”. I’ve only just glanced through the paper.  I find it interesting, but I’m fairly skeptical.  The … Continue reading...

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Hipster programming languages

September 26, 2011
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Hipster programming languages

If you look at the programming languages that are popular these days, a few patterns emerge. I'm not talking about languages that have the most hits on the job sites. I'm talking about what the cool kids are coding in - the folks that hang out on hacke...

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Revolution Analytics partners with Cloudera

September 26, 2011
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Revolution Analytics today announced that it has partnered with Cloudera, the leader in Apache Hadoop-based software and services, to make big-data analytics with Hadoop and R available to Revolution R Enterprise users. As we announced earlier this month, we have created three open-source R packages which make it possible for R users to write map-reduce programs in the R...

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ttrTests: Its Great Thesis and Incredible Potential

September 26, 2011
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ttrTests: Its Great Thesis and Incredible Potential

I stumbled on the ttrTests R package as mentioned in my post ttrTests Experimentation.  I did not recognize its potential until I spent much more time absorbing the basis of the package—David St. John’s thesis Technical Analysis Based on Movin...

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workshop in Columbia [day 3]

September 26, 2011
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workshop in Columbia [day 3]

Although this was only a half-day of talks, the third day of the workshop was equally thought-challenging and diverse.  (I managed to miss the ten first minutes by taking a Line 3 train to 125th street, having overlooked the earlier split from Line 1… Crossing south Harlem on a Sunday morning is a fairly mild

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Using Inkscape to Post-edit Labels in R Graphs

September 26, 2011
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I discuss how to use Inkscape to easily shift around labels on graphs produced in R. Continue reading →

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Gamified

September 26, 2011
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Gamified

Barry Rowlingson gave an interesting talk at UseR 2011, “Why R-help must die!” He suggested the Q-and-A type sites Stack Overflow (on programming) and Cross Validated (on statistics), both part of Stack Exchange. An interesting feature of these sites is that, in addition to voting up and down on the questions and answers, one accrues

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Visualizing Sampling Distributions

September 25, 2011
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Visualizing Sampling Distributions

Teacher: “How variable is your estimate of the mean?” Student: “Uhhh, it’s not. I took a sample and calculated the sample mean. I only have one number.” Teacher: “Yes, but what is the standard deviation of sample means?” Student: “What do you mean means, I only have the one friggin number.” Statisticians have a habit

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Accessing and plotting World Bank data with R

September 25, 2011
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Accessing and plotting World Bank data with R

Over the past couple of days I played around with the data sets of the World Bank, and I have to admit that I am blown away by it. It is amazing, to see what is available on their web site. It is worth visiting their Data Visualisation Tools page. It i...

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rrdf 1.5: Accessing SMW SPARQL end points behind LDAP authentication

September 25, 2011
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rrdf 1.5: Accessing SMW SPARQL end points behind LDAP authentication

We are using a Semantic MediaWiki (SMW) for the Gold Compound selection task by the ToxBank in the SEURAT-1 cluster, funded by Colipa and the EC. I do stress that despite being funded by Colipa, they have no control over my research; they just co-...

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Arc Diagram and spatiotemporal data mining visualization

September 23, 2011
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Arc Diagram and spatiotemporal data mining visualization

I won't spend too much time discussing this fascinating topic other than to say it relates very much to prior discussions about pattern discovery via visual data mining (see lexical dispersion plots for example).  I happened across an interesting ...

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Nice Species Distribution Maps with GBIF-Data in R

September 23, 2011
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Nice Species Distribution Maps with GBIF-Data in R

Here's an example of how to easily produce real nice distribution maps from GBIF-data in R with package maps... Read more »

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Data Visualization doesn’t need to be biased

September 23, 2011
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Data Visualization doesn’t need to be biased

At the FlowingData blog, data visualization commentator and Visualize This author Nathan Yau lists 5 misconceptions about visualization: Software does everything (Nathan notes "Personally, I use a lot of R and have a lot of fun in Illustrator", but uses a lot of other tools as well.) Visualization is for making data flashy The more information in a single...

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Kaggle on TV

September 22, 2011
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It is good to see forecasting algorithms getting some mainstream exposure on ABC Catalyst.

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craps 0.1

September 22, 2011
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craps 0.1

The following script simulates a craps game in R any number of iterations with any starting amount of cash and any maximum odds and running until the user is out of cash.  It assumes a specific betting strategy as explained … Continue reading →

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Facebook page about the Graph Gallery

September 22, 2011
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Facebook page about the Graph Gallery

I've just created a facebook page about the R Graph Gallery I hope this will improve the experience of the website by making it more social, for example, I anticipate that people will share their own graphs by sending a picture on the facebook ...

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Are new SEC rules enough to prevent another Flash Crash?

September 22, 2011
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Are new SEC rules enough to prevent another Flash Crash?

At 2:42PM on March 10 2010, without warning, the Dow Jones Industrial Index plunged more than 1000 points in just 5 minutes. It remains the biggest one-day decline in this stock market index in history. On an intra-day basis, anyway: by the end of the day, the market had regained 600 points of the drop. At the time, the...

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Slides and replay from "R and Hadoop" webinar

September 21, 2011
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Slides and replay from "R and Hadoop" webinar

So ... there's clearly a lot of interest in integrating R and Hadoop. Today's webinar was a record-setter for Revolution Analytics, with more than 1000 people signing up to learn how to access Hadoop data from R with the packages from the open-source RHadoop project. If you didn't catch the live webinar, don't fret: the slides and replay are...

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Go vector or go home

September 21, 2011
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My programming experience progressed mostly along the lines of: C, C++, shell, Java, Java, Ruby, Python, Java, Java. Only recently have I started exploring the likes of Haskell, Erlang and R. Well that evolution bit me a little while back when I tried ...

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digest 0.5.1

September 21, 2011
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A new version of the digest package (which generates hash function summaries for arbitrary (and possibly nested) R objects using any of the standard md5, sha-1, sha-256 or crc32 algorithms) is now on CRAN. Bryan Lewis, who is doing very stuff with ...

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Strangeloop 2011 Day 2

September 21, 2011
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Strangeloop 2011 Day 2

I’m headed back home from Strangeloop 2011 this morning. Once again I booked an early flight so was up at 4:45 to get to the airport (when will I learn?) The conference was a smashing success as far as I am concerned. It was extremely well run and the talks were full of solid content.

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Handbook of Markov chain Monte Carlo

September 21, 2011
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Handbook of Markov chain Monte Carlo

At JSM, John Kimmel gave me a copy of the Handbook of Markov chain Monte Carlo, as I had not (yet?!) received it. This handbook is edited by Steve Brooks, Andrew Gelman, Galin Jones, and Xiao-Li Meng, all first-class jedis of the MCMC galaxy. I had not had a chance to get a look at

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More facebook and google plus on the Graph Gallery

September 21, 2011
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More facebook and google plus on the Graph Gallery

Following up on yesterday's post about facebook like box, I've added some more social things into the gallery. The main page gains a google plus "plus one" button, and each graph page now has a +1 button, a facebook like button, and a facebook comm...

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Simple plot using R

September 21, 2011
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Simple plot using R

As a task for my Financial eco assignment I had to plot a simple time series of the overnight MIBOR(Mumbai interbank offer rates) for the past one year . The job could very well have been done easily in MS-Excel but I choose to plot it in R instea...

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Project Euler: problem 3

September 21, 2011
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Project Euler: problem 3

The prime factors of 13195 are 5, 7, 13 and 29.What is the largest prime factor of the number 600851475143 ?This one was quite easy, and much easier in R as it turns out.The GNU Multi-Precision Library (GMP) is available as a package in R. So the only ...

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Variogram fit with RPanel

September 21, 2011
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Variogram fit with RPanel

During the UseR 2011 conference I saw lots of examples of the use of RPanel to create a GUI in R. Yesterday, because I was a bit bored of the work I was doing I started thinking about this and I decided to try this package.My objective was to create a new panel with all the main setting for...

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A Note on Antoniak’s Approximation for Dirichlet Processes

September 21, 2011
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A Note on Antoniak’s Approximation for Dirichlet Processes

Antoniak's 1974 article titled Mixtures of Dirichlet Processes with Applications to Bayesian Nonparametric Problems (Annals of Statistics 2(6):1152-1174) is a fundamental work for most modern developments in this area. The article gives two expressions for the expected number of distinct values in a sample of size n, drawn from a Dirichlet process-distributed probability distribution with

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Solvency 2 WordCloud

September 21, 2011
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Slow day at PSY headquarters: Click see wordleWe grabbed the Solvency II directive text from the EC website (© European Union, http://eur-lex.europa.eu/) and ran it through a couple of lines of R code to draw up wordcount frequencies. Then we plotted the text in Wordlehttp://www.wordle.net/show/wrdl/4111834/Solvency_2We're not convinced about the utility of WordClouds, but they look cool....

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Example 9.6: Model comparison plots (Completed)

September 21, 2011
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Example 9.6: Model comparison plots (Completed)

We often work in settings where the data set has a lot of missing data-- some missingness in the (many) covariates, some in the main exposure of interest, and still more in the outcome. (Nick describes this as "job security for statisticians").Some ana...

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