Magnetic Resonance Imaging in R

December 29, 2011
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Volume 44 of the Journal of Statistical Software was published in October 2011.  The special volume on “Magnetic Resonance Imaging in R” features articles and packages related to a variety of imaging modalities:functional MRIdiffusion-weighted MRIdynamic contrast-enhanced MRIdynamic susceptibility-contrast MRI structural MRIThe papers describe the methodology, software implementation and provide comprehensive examples and data. ...

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How much is a shower?

December 29, 2011
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How much is a shower?

After looking at my heating expenses, I turned to the costs for water heating. For some time, I looked at my water meter before and after taking a shower or a bath. Quite often, I forgot one or the other measurement, but I collected about 40 observations. Here is what they look like:The data suggest that for a...

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New version of the Rcmdr package

December 29, 2011
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This is the massage sent by John Fox to the R-pkgs mailing list: Dear R users, I’d like to announce a new version, 1.8-1, of the Rcmdr package. The Rcmdr (“R Commander”) package provides a basic-statistics graphical user interface (GUI) to R, implemented in Tcl/Tk via the standard R tcltk package. Beyond small changes and additions, the new version of...

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Japan Stagnation Myth?

December 28, 2011
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Japan Stagnation Myth?

I came across this piece on The Atlantic website by Eamonn Fingleton arguing that Japan's two decade long stagnation is largely a myth. I'm not willing, just yet, to completely go along with his thesis that this myth has been stoked by the Japanes...

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Top Grossing Movies by Year (U.S.)

December 28, 2011
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Top Grossing Movies by Year (U.S.)

Description:Top grossing movie year by year, adjusted for inflation.Data:http://thenumbers.comAnalysis:This is a bit of an odd chart.  It only shows the total gross of the highest grossing movie for each year.  When adjusted for inflation, 'G...

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R-specific review of blog year 2011

December 28, 2011
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R-specific review of blog year 2011

Most popular posts Two of the ten most popular posts during the year were completely about R: The R Inferno revised (number 6) Solve your R problems (number 9) R played a role in the other eight top ten, and many of the rest of the posts as well. R The R Inferno was revised … Continue reading...

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Heating costs

December 28, 2011
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Heating costs

In 2010, my heating costs exceeded my advance payments by about 25%. This motivated me to decompose the costs to see what drove the changes. Here is the result:The numbers refer to Euros. Read von right to left: 2010 was a cold year (+102EUR), but gas consumption in this house was relatively low (–89EUR). Also, running costs and...

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Homicides in Mexico 2010

December 28, 2011
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Homicides in Mexico 2010

Recently the Mexican government released to the public the final homicide data for 2010, and as you can see from the chart Mexico has suffered from a steep rise in homicides since 2008, and in 2010 reached the highest homicide rate in recent history. The Mexican government had actually released preliminary homicide data...

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Rcpp 0.9.9

December 27, 2011
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Release 0.9.9 of Rcpp is now on CRAN and getting into Debian too. This is mainly a bug fix release: our addition of int64 support in 0.9.8 came at the expense of support for long and unsigned long which broke some packages using Rcpp, and expecting t...

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oro.nifti 0.3.1

December 27, 2011
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oro.nifti 0.3.1

The  package oro.nifti contains functions for the input/output and visualization of medical imaging data that follow either the ANALYZE, NIfTI or AFNI formats.  This package is part of the Rigorous Analytics bundle.Lightbox display of fu...

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Web scraping with Python – the dark side of data

December 27, 2011
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In searching for some information on web-scrapers, I found a great presentation given at Pycon in 2010 by Asheesh Laroia. I thought this might be a valuable resource for R users who are looking for ways to gather data from user-unfriendly websites. The...

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oro.dicom 0.3.3

December 27, 2011
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oro.dicom 0.3.3

The R package oro.dicom contains data input/output functions for medical imaging data that conform to the Digital Imaging and Communications in Medicine (DICOM) standard, part of the Rigorous Analytics bundle.The latest version of oro.dicom (0.3.3) con...

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Fed Loan Data Part 1

December 27, 2011
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Fed Loan Data Part 1

This is the start of analyzing the Federal Reserve and Banking data mentioned in my "A Christmas Miracle". The file is a combination of summary data and actual data from each of the 400+ banks that recieved funds from the Federal Reserve during 2007-20...

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Monetary Policy and Credit Easing

December 26, 2011
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Here at the dancing economist, we wish to educate our followers on the finer points of economics and this includes econometrics and using R. R as mentioned previously is a free statistical software that enables regular people like us to do high end eco...

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Just Crantastic!

December 26, 2011
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If you're an econometrician and you don't use the R software environment - for at least some of your work, then you're missing out on all sorts of (free!) opportunities.Yes, it can be a steep learning curve, but it's worth every drop of sweat, and there are some great R community sites that will help you along...

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Modelling returns using PCA : Evidence from Indian equity market

December 26, 2011
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As my finance term paper, I investigated an interesting question where I tried to identify macroeconomic variables that explain the returns on equities. Much of the debate has already taken place on this topic which has given rise to two competing theo...

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An R wish list for 2012

December 26, 2011
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An R wish list for 2012

I expect there will be many reviews and wish lists for R this year, with many of them focusing on either running speed or dealing with large data sets. However, most issues that I would like to see tackled in … Continue reading →

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Le Monde puzzle [#754]

December 25, 2011
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Le Monde puzzle [#754]

The pre-X’mas puzzle in Le Monde weekend edition is about “magical numbers” having as digits all digits between 0 and n (at least once) and being multiple of all digits between 1 and (n+1). Easy, isn’t it?! I thought so while driving down to the Alps on Saturday and (on Monday early morning) I tried

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Portfolio Optimization in R, a previous error.

December 25, 2011
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I realized that I made a mistake in the calculation of the market weight portfolio from the previous post.  I hold constant the portfolio weights through time. These should be adjusted after each day as prices change.  The market portfolio re...

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Portfolio Optimization in R, a previous error.

December 25, 2011
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Portfolio Optimization in R, a previous error.

I realized that I made a mistake in the calculation of the market weight portfolio from the previous post.  I hold constant the portfolio weights through time. These should be adjusted after each day as prices change.  The market portfolio re...

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R and the Geotechnical Exchange Format

December 24, 2011
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R and the Geotechnical Exchange Format

Quite some time ago now, I wrote this function to read some *.gef files into R. "gef" stands for Geotechnical Exchange Format. Details on this data format can be found at http://www.geffiles.nl/, as well as several software tools. I had a long list of ...

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Call for Abstracts for useR! 2012

December 24, 2011
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The international R User Conference useR! 2012 will be held June 12-15 at Vanderbilt University in Nashville, Tennessee, USA, with a pre-conference full-day course offered on June 11. Participants are encouraged to submit a one-page abstract for oral or poster presentation at the conference. Half-day tutorials will be held in the morning and afternoon of June 12th. For tutorials,...

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ML-Class Ex 7 – kMeans clustering

December 24, 2011
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ML-Class Ex 7 – kMeans clustering

The K-means algorithm is a method to automatically cluster similar data examples together. The intuition behind K-means is an iterative procedure that starts by guessing the initial centroids, and then refines this guess by repeatedly assigning examples to their closest centroids and then recomputing the centroids based on the assignments. Read more »

Recology is 1 yr old

December 23, 2011
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Recology is 1 yr old

This blog has lasted a whole year already.  Thanks for reading and commenting. There are a couple of announcements: Less blogging: I hope to put in many more years blogging here, but in full disclosure I am blogging for Journal of Ecology now, ...

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Recology is 1 yr old

December 23, 2011
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Recology is 1 yr old

This blog has lasted a whole year already.  Thanks for reading and commenting. There are a couple of announcements: Less blogging: I hope to put in many more years blogging here, but in full disclosure I am blogging for Journal of Ecology now, ...

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Recology is 1 yr old…

December 23, 2011
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Recology is 1 yr old…

This blog has lasted a whole year already.  Thanks for reading and commenting. There are a couple of announcements:Less blogging:  I hope to put in many more years blogging here, but in full disclosure, I am blogging for Journal of Ecology no...

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A Christmas Miracle

December 23, 2011
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Data files on 407 banks, between the dates of 2007 to 2009, on the daily borrowing with the US Federal Reserve bank. The data sets are available from Bloomberg at this address data This is an unprecedented look into the day-to-day transactions of ...

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Programming traps when using "sample"

December 23, 2011
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Programming traps when using "sample"

Standard sample function works differently when it gets single element integer vector as opposed to longer vectors. This can lead to unexpected bugs in R code.Several times I had a problem with code similar to one given here:for (i in 1:4) {&...

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Norman Nie on two big problems with Big Data

December 23, 2011
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Revolution Analytics CEO Norman Nie sat down with Cassimir Medford from Business Agility to talk about the problems business today face with respect to Big Data. The two big problems identified: finding adequately trained personnel and locating the right tools. Norman traces the problem of finding skilled practitioners to work with Big Data to the US educational system: The...

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