Comparison of Sunil Gavaskar and Javed Miandad’s Performance in International Cricket

October 2, 2010
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Comparison of Sunil Gavaskar and Javed Miandad’s Performance in International Cricket

Test Cricket PerformanceOne Day Cricket Performance

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A new version of ff released (version 2.2.0)

October 2, 2010
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A few hours ago, Jens Oehlschlägel has announced on the R-help mailing list of the release of a new version of the ff package. The ff package provides data structures that are stored on disk but behave (almost) as if they were in RAM by transparently mapping only a section (pagesize) in main memory – the effective virtual memory...

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OpenMx 1.0

October 1, 2010
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Just realized that this SEM package for R has released version 1.0. Great...

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OpenMx 1.0

October 1, 2010
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Just realized that this SEM package for R has released version 1.0. Great...

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Because it’s Friday: I hate pennies

October 1, 2010
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I was brought up in Australia, where we got rid of 1¢ and 2¢ coins in my childhood. Nobody missed them, at least as I recall. I certainly didn't: they were useless, even at the age when I might by lollies (candy) for 2¢ apiece. But then again, I'd never buy one, and with the new changes if I...

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Fibonacci 1-liners

October 1, 2010
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The other day, as an excuse to play around with custom iterators, I created some completely over-engineered code to calculate the Fibonacci sequences. But surely such a simple function can be implemented in fewer than my 15 lines? (Rick Wicklin, who writes the SAS blog The Do Loop, thinks so too.) We could use such a function to more...

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R Beginner’s Guide Book Update 10/1/2010

October 1, 2010
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R Beginner’s Guide Book Update 10/1/2010

Update: Statistical Analysis with R is now available!I recently submitted the final drafts of all chapters of my R Beginner's Guide book, which is to be published through Packt. The official publishing timeline is set to December 2010, although the boo...

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R Beginner’s Guide Book Update 10/1/2010

October 1, 2010
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R Beginner’s Guide Book Update 10/1/2010

Update: Statistical Analysis with R is now available!I recently submitted the final drafts of all chapters of my R Beginner's Guide book, which is to be published through Packt. The official publishing timeline is set to December 2010, although the boo...

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Three-Quarter Truths: Correlation Is Not Causation

October 1, 2010
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Three-Quarter Truths: Correlation Is Not Causation

Other than our culture’s implicit association between lies, damned lies and statistics, I think no idea has stifled the growth of statistical literacy as much as the endless repetition of the words correlation is not causation. This phrase seems to be primarily used to suppress intellectual inquiry by encouraging the unspoken assumption that correlational knowledge

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R Optimization Function Test

R Optimization Function Test

Using Kalman Filter for CIR interest rate model parameter estimation was introduced at my previously post Kalman Filter finance, soon after that I got a few comments saying the final results are unstable and highly depend on the initial values, that's...

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Managing a statistical analysis project – guidelines and best practices

September 30, 2010
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Had to share this link today as I better read all the content it refers to and incorporate a lot of the recommended practices into my work flow. Thanks Tal Galili for compiling all those information.

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Mandelbrot Set, evolved

September 30, 2010
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Mandelbrot Set, evolved

The Mandelbrot Set is perhaps the most famous fractal of all time. It's simple in its definition: iterate the complex equation zn+1 = zn2 + c (starting with z0 = 0) for various values of c, and if doesn't go to infinity then c is part of the Mandelbrot Set. The result, however, is amazingly complex. Thinking of c...

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Plotting Time Series data using ggplot2

September 30, 2010
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Plotting Time Series data using ggplot2

There are various ways to plot data that is represented by a time series in R. The ggplot2 package has scales that can handle dates reasonably easily. Fast Tube by Casper As an example consider a data set on the number of views of the you tube channel ramstatvid. A short snippet of the data is shown

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Managing a statistical analysis project – guidelines and best practices

September 30, 2010
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In the past two years, a growing community of R users (and statisticians in general) have been participating in two major Question-and-Answer websites: The R tag page on Stackoverflow, and Stat over flow (which will soon move to a new domain, no worries, I’ll write about it once it happens) In that time, several long (and fascinating) discussion threads where started,...

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New version of solaR

September 30, 2010
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New version of solaR

The version 0.2 of the solaR package is now available at CRAN. This package provides a set of calculation methods of solar radiation and performance of photovoltaic systems. The package has been uploaded to CRAN under the GPL-3 license. The most important changes included in this version are: The package is now almost entirely designed

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Moshtemp 5.1

September 29, 2010
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Moshtemp 5.1

Time for another dump of the entire package. Get the zip file 5.1 in the box to the right. ( shortly). unzip and run the following files if you havent already: 1. downloadall.R 2. setup.R If you are running for the first time, You’ll note I added diagnostics. Sometimes the files get corrupted on download

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Le Monde puzzle [38]

September 29, 2010
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Le Monde puzzle [38]

Since I have resumed my R class, I will restart my resolution of Le Monde mathematical puzzles…as they make good exercises for the class. The puzzle this week is not that exciting: Find the four non-zero different digits a,b,c,d such that abcd is equal to the sum of all two digit numbers made by picking

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NewTwitter design based on a Golden Spiral

September 29, 2010
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NewTwitter design based on a Golden Spiral

I finally got the new version of Twitter yesterday, and it looks great. And that's no accident: according to the designer, the layout of the new Twitter interface is based on the Golden Spiral: You can describe the Golden Spiral by laying consecutive squares in a spiral fashion, each square being smaller than the last by a factor of...

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UCLA Statistics: Analyzing Thesis/Dissertation Lengths

September 29, 2010
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UCLA Statistics: Analyzing Thesis/Dissertation Lengths

As I am working on my dissertation and piecing together a mess of notes, code and output, I am wondering to myself “how long is this thing supposed to be?” I am definitely not into this to win the prize for longest dissertation. I just want to say my piece, make my point and move on. I’ve heard that...

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A Visualization of Soil Taxonomy Down to the Subgroup Level

September 29, 2010
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A Visualization of Soil Taxonomy Down to the Subgroup Level

It turns out that you can generate a quasi-numerical distance between soil profiles classified according to Soil Taxonomy (or any other hierarchical system) using Gower's generalized dissimilarity metric. For example, taxonomic distances computed from ...

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Cooling stations. A UHI Hint

September 29, 2010
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Cooling stations. A UHI Hint

Update: google earth files in the box: Personally I like to look at things backwards. Why are cool sites cool? So download the kml or kmz file and you can tour 62 sites: All with 90 years of data or more. All with a cooling trend. And all “supposedly” urban. what do you see at

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Mike’s and my book is coming out

September 29, 2010
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Mike’s and my book is coming out

Our book is finally coming out: You can buy it on Amazon.com, Amazon.de, or Springer.com.

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Mike’s and my book is coming out

September 29, 2010
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Mike’s and my book is coming out

Our book is finally coming out: You can buy it on Amazon.com, Amazon.de, or Springer.com.

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Some Oddities with cooling stations

September 29, 2010
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Some Oddities with cooling stations

Now, that  the whole analysis has been moved to raster, I took some time to play around with a question that has interested  a couple of people. Cool stations. A while back when I was looking at ways of bounding uncertainties in the record I went on a hunt for the station that cooled the

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A texteditor for R

September 29, 2010
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A texteditor for R

I’ve been using RWinEdt for the last few years for all my R coding. But it no longer works with WinEdt 6.0 and no update has been forthcoming. Consequently, I’ve been looking around for something similar to take its place. This question has been asked before on StackOverflow and many suggestions were made including popular

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Forecasting with long seasonal periods

September 28, 2010
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Forecasting with long seasonal periods

I am often asked how to fit an ARIMA or ETS model with data having a long seasonal period such as 365 for daily data or 48 for half-hourly data. Generally, seasonal versions of ARIMA and ETS models are designed for shorter periods such as 12 for monthly data or 4 for quarterly data. The

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Google Summer of Code advances R

September 28, 2010
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For the third year running, the Google Summer of Code program has sponsored a number of students working with R, and has again resulted in several new contributions expanding R in various fields. Dirk Eddelbuettel, who coordinated the R-related projects for GSoC in 2010, summarized the results, with details about the new packages now available for R thanks to...

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Example 8.7: Hosmer and Lemeshow goodness-of-fit

September 28, 2010
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Example 8.7: Hosmer and Lemeshow goodness-of-fit

The Hosmer and Lemeshow goodness of fit (GOF) test is a way to assess whether there is evidence for lack of fit in a logistic regression model. Simply put, the test compares the expected and observed number of events in bins defined by the predicted p...

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A Slider to Control Two Plotting Windows

September 28, 2010
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One of my readers asked two weeks ago how to control two graphics windows with the slider in gWidgets. Here is a simple example: if (!require("gWidgetsRGtk2")) install.packages("gWidgetsRGtk2") library(gWidgetsRGtk2) options(guiToolkit = "RGtk2") graphics.off() x11() x11() dev.set() gslider(from = 1, to = 100, value = 10,     container = gwindow("Two Plotting Windows"), handler = function(h, ...) {

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