How to Install R for Windows and Use a Few Basic Functions

February 20, 2012
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This video shows how to obtain and install R on the Windows (PC) platform. It also shows a few basic functions in R, such as how to install packages in R and load them for use.

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Reading huge files into R

February 19, 2012
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SAS is much touted for its ability to read in huge datasets, and rightly so. However, that ability comes at a cost: for smaller datasets, since files remain on the disk rather than in memory (as is the case with Stata and R), it is potentially less fa...

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makeR: An R Package for Managing Document Building and Versioning

February 19, 2012
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If you are reading this vis-à-vis R-Bloggers, then you know how good R, LaTeX, and Sweave are for generating reports and/or conducting reproducible research. It has been particularly valuable for me in Institutional Research where there are many reports that I need to prepare on a regular basis (some monthly, some quarterly, some annually). However, one issue

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Cross validated question

February 19, 2012
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Cross validated question

Another problem generated by X’validated (on which I spent much too much time!): given an unbiased coin that produced M heads in the first M tosses, what is the expected number of additional tosses needed to get N (N>M) consecutive heads? Consider the preliminary question of getting a sequence of N heads out of k

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Standard Normal Variate (SNV)

February 19, 2012
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Standard Normal Variate (SNV)

(This article was first published on NIR-Quimiometría, and kindly contributed to R-bloggers) This is another pretreatment used quite often in Near Infrared to remove the scatter. It is applied to every spectrum individually. The average and standard deviation of all the data points for that spectra is calculated. Every data point of the spectra is substracted from the mean and...

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Live Rolling Correlation Plot

February 19, 2012
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Open source is amazing! I cannot even start to imagine the amount of work invested in R, in firefox browser (Mozilla), or Rstudio IDE, all of which are used extensively around the globe, free. Not free as in: free sample … Continue reading →

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R for Quants, Part III (A)

February 18, 2012
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R for Quants, Part III (A)

This is the third part in a three part series on teaching R to MFE students at CUNY Baruch. The …Continue reading »

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Maps with R (I)

February 18, 2012
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Maps with R (I)

This is the first post of a short series to show some code I have learnt to produce maps with …Continuar leyendo »

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Using Rcout with Rcpp / RcppArmadillo to coordinate output with R

February 18, 2012
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The new RcppArmadillo release 0.2.35 now supports the Rcpp::Rcout output stream device. Based on a contributed Rcpp patch by Jelper Ypma, the Rcpp::Rcout output stream gets redirected to R's buffered output. In other words, R's own output and that e...

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How-to Extract Text From Multiple Websites with R

February 18, 2012
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How-to Extract Text From Multiple Websites with R

I have been meaning to post this slideshow for awhile now. It gives a brief introduction to using R for scraping text from multiple websites. It includes some basic debugging, because R sometimes misses a website.Just click the arrows to change the sli...

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Mid-February flotsam

February 17, 2012
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Mid-February flotsam

This coming Monday we start the first semester in Canterbury (and in New Zealand for that matter). We are all looking forward to an earthquake-free year; more realistically, I’d be happy with low magnitude aftershocks. The Wall Street Journal reports … Continue reading →

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doSMP removed from CRAN

February 17, 2012
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doSMP removed from CRAN

If you do parallel processing in R on Windows, then you probably have heard of the doSMP package. However, it was recently removed from the CRAN repository with the terse message: Package ‘doSMP’ was removed from the CRAN repository. Revolution … Continue reading →

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R in Financial Services Viewpoint newsletter

February 17, 2012
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The Winter 2012 edition of Sybase's Financial Services Viewpoint newsletter includes two articles related to R. The "Industry Insight" article "R is Hot" (written by yours truly) is a one-page summary of the R phenomenon: what it is, how it's used, and how it's revolutionizing data analysis. The "Industry Insight" article by SAP's Melinda Wilson, "R swings the pendulum...

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RcppArmadillo 0.2.35

February 17, 2012
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Now that Rcpp 0.9.10 is released and on CRAN, other packages can take advantage of a small change needed to make use of the quasi-output stream Rcpp::Rcout. So the new release 0.2.35 of RcppArmadillo does just that---and input/output from Armadillo...

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Visualizing the Correlations of a Matrix

February 17, 2012
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Visualizing the Correlations of a Matrix

Correlation matrices are a common way to look at the dependence of a set of variables. When the variables have spatial relationships, the correlation matrix loses some information.Lets say you have repeated observations, each one being a matrix. For ex...

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Plotting the “Mean Spectrum”

February 17, 2012
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Plotting the “Mean Spectrum”

(This article was first published on NIR-Quimiometría, and kindly contributed to R-bloggers) Mean spectrum calculation is important: To center a matrix of spectra, we subtract the mean spectrum, from every spectrum in the matrix. There are also many options to use the mean spectrum, like average subsamples. Let´s calculate and plot the mean spectra for the Yarn NIR Data:...

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Visualising Twitter User Timeline Activity in R

February 17, 2012
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Visualising Twitter User Timeline Activity in R

I’ve largely avoided “time” in R to date, but following a chat with @mhawksey at #dev8d yesterday, I went down a rathole last night exploring a few ways of visualising a Twitter user timeline and as a result also had a quick initial play with some time handling features of R, such as timeseries objects,

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Rcpp 0.9.10

February 17, 2012
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A new release 0.9.10 of Rcpp is now on CRAN and in Debian. This is mostly internal release with a little bit of code reorgination (some of which will be used by a forthcoming RcppArmadillo release), some changes to make R CMD check happy, and one or ...

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Course: Statistical Practice in Epidemiology with R

February 17, 2012
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Course: Statistical Practice in Epidemiology with R

Statistical Practice in Epidemiology with R is a one week course aimed at promoting the use of R among epidemiologists.  This annual course has been running almost every year since 2004. Last year it took place in Lyon, France, but … Continue reading →

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10,000 R Questions on Stackoverflow

February 17, 2012
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10,000 R Questions on Stackoverflow

I was browsing stackoverflow when suddenly I noticed: 10 thousand questions tagged! I started using Stackoverflow almost exactly a year ago and remember that the counter was about 3 thousand at the time. It is a beautiful example of how fast the R community is … Continue reading →

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draw chinese character Jiong using ggplot2

February 17, 2012
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draw chinese character Jiong using ggplot2

The Chinese character Jiong (囧) is now widely used for expressing ideas or feelings such as annoyance, shock, embarrassment, awkwardness, scorn. The function plot of y=1/(x^2-1) looks very similar of this symbol. I use ggplot2 to draw the symbol of Jiong. Read More: 359 Words Totally

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Useful functions for data frames in R

February 17, 2012
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This post will consider some useful functions for dealing with data frames during data processing and validation. Consider an artifical data set create using the expand.grid function where there are duplicate rows in the data frame. > des = expand.grid(A = c(2,2,3,4), B = c(1,3,5,5,7)) > des A B 1 2 1 2 2 1

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Take the INNGE survey on math and ecology

February 17, 2012
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Many ecologists are R users, but we vary in our understanding of the math and statistical theory behind models we use. There is no clear consensus on what should be the basic mathematical training of ecologists. To learn what the community thinks, we ...

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R hits 10000 questions on stackoverflow

February 17, 2012
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R hits 10000 questions on stackoverflow

A milestone, though not that exciting as questions go. Still, if you haven’t yet joined the cult of Stack Exchange, take a look here. Tagged: r, stackoverflow

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R for Quants, Part II (A)

February 16, 2012
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R for Quants, Part II (A)

This is the second part in a three part series on teaching R to MFE students at CUNY Baruch. The …Continue reading »

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Machine Learning for Hackers

February 16, 2012
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Machine Learning for Hackers

"Machine Learning for Hackers" is a new book from O'Reilly Media by Drew Conway and John Myles White. A "hacker", here, is "someone who likes to solve problems and experiment with new technologies", and "Machine Learning" is usually thought of as a black-box, algorithmic approach to producing predictions or classifications from data. This book, however, takes a pleasingly statistical...

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How to Install R for Mac and Use a Few Basic Functions

February 16, 2012
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This video shows how to obtain and install R on the Mac OS X platform. It also shows a few basic functions in R, such as how to install packages in R and load them for use. A PC version will follow shortly.

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How to Install R for Mac and Use a Few Basic Functions

February 16, 2012
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This video shows how to obtain and install R on the Mac OS X platform. It also shows a few basic functions in R, such as how to install packages in R and load them for use. A PC version will follow shortly

Reflect your Personnel Selection: R & Taylor-Russell Tables

February 16, 2012
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Reflect your Personnel Selection: R & Taylor-Russell Tables

Taylor-Russell tables (Taylor & Russell, 1939) are designed to estimate the percentage of future employees who will be successful on the job if a particular selection method (eg. test, assessment center, interview) is used. I have already described the kibit … Weiterlesen →

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