Bootstrapping a Single Statistic (k=1) The following example…

November 1, 2011
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Bootstrapping a Single Statistic (k=1) The following example generates the bootstrapped 95% confidence interval for R-squared in the linear regression of miles per gallon (mpg) on car weight (wt) and displacement (disp). The data source is mtcars. The...

Web Scraping Google Scholar & Show Result as Word Cloud Using R

November 1, 2011
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OUTDATED! Please see the update HERE!...When reading Scott Chemberlain's last post about web-scraping I felt it was time to pick up and complete an idea that I was brooding over for some time now:When a scientist aims out for a new project the firs...

Minimizing Downside Risk

November 1, 2011
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$Minimizing Downside Risk$

In the Maximum Loss and Mean-Absolute Deviation risk measures, and Expected shortfall (CVaR) and Conditional Drawdown at Risk (CDaR) posts I started the discussion about alternative risk measures we can use to construct efficient frontier. Another alternative risk measure I want to discuss is Downside Risk. In the traditional mean-variance optimization both returns above and

How Might Data Journalists Show Their Working? Sweave

November 1, 2011
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If part of the role of data journalism is to make transparent the justification behind claims that are, or aren’t, backed up by data, there’s good reason to suppose that the journalists should be able to back up their own data-based claims with evidence about how they made use of the data. Posting links to

Line Plots (Econometric in R) Input: ##…

November 1, 2011
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Line Plots (Econometric in R) Input: ## ---------------------------- ## ## Plotting Points *and* Lines ## ## ---------------------------- ## pow = c(0.95, 0.6, 0.3, 0.15, 0.1, 0.05, 0.1, 0.15, 0.3, 0.6, 0.95) pow2 = c(0.99, 0.75, 0.4, 0.2, 0.15, 0.0...

Etiquette on the mailing list, to RTFM or not to RTFM

November 1, 2011
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Sometimes people ask very basic questions on the R-help mailing list, which could have easily been answered by reading some R manual or doing a quick Google search. Responses on the mailing range from people answering the question to “Please… See more ›

Project Euler-Problem 38

November 1, 2011
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Take the number 192 and multiply it by each of 1, 2, and 3: 192 × 1 = 192 Read More: 450 Words Totally

Halloween 2011 count

October 31, 2011
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We don’t get many kids seeking candy at our house. I’m not sure if there just aren’t many kids in the neighborhood, or if it’s our location (next to the pond, with a big gap before the next house). I decided to keep track. As usual, we bought a huge bag of candy, and we

Japan Quake Map

October 31, 2011
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Japan Quake Map with R, ggplot2, and FFmpeg   1 Introduction As a follow-up to ‘Analysis of Japanes

Covered Call ETF Performance

October 31, 2011
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Covered call ETFs have become quite popular lately. Living in Canada, I have been holding a couple Canadian members of this family for the last few months. When I purchased them, I liked the benefits and since I wasn’t expecting any bull markets on the horizon, I bought some. These were new products back them,

Putting the R in Hallowe’en

October 31, 2011
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PhD student Caroline Tucker created a Hallowe'en card using the R graphics system: You can find the R code to create the above image here. Note that you'll need to install the fields and MBA packages first. One interesting aspect of the code is the use of the mba.surf function to create the shading that gives the Jack-o'-lantern its...

Using Sparse Matrices in R

October 31, 2011
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Introduction I’ve recently been working with a couple of large, extremely sparse data sets in R. This has pushed me to spend some time trying to master the CRAN packages that support sparse matrices. This post describes three of them: the Matrix, slam and glmnet packages. The first two packages provide data storage classes for

R 2.14.0 Released

October 31, 2011
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A Halloween treat for R users! Version 2.14.0 was released today. Among other things there are big improvements for parallel processing. For a quick synopsis of the new "goodies", see the post on the Revolutions blog.© 2011, David E. Giles

Plotting grouped data vs time with error bars in R

October 31, 2011
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This is my first blog since joining R-bloggers. I’m quite excited to be part of this group and apologize if I bore any experienced R users with my basic blogs for learning R or offend programmers with my inefficient, sloppy … Continue reading →

Plotting grouped data vs time with error bars in R

October 31, 2011
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This is my first blog since joiningR-bloggers. I’m quite excited to be part of this group and apologize if I boreany experienced R users with my basic blogs for learning R or offendprogrammers with my inefficient, sloppy coding. Hopefully writing for...

useR! 2011 – Jonathan Rougier: Nomograms for visualising relationships between three variables

October 31, 2011
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useR2011 – Rougier View more presentations from rusersla

useR! 2011 – Wolfgang Huber: Genomes and phenotypes

October 31, 2011
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useR2011 – Huber View more presentations from rusersla

Making R’s paste act more like CONCAT

October 31, 2011
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While vector-friendly, R's paste function has a few behaviors I don't particularly like. One is using a space as the default separator:> adjectives> paste(adjectives,"er")> paste(adjectives,"er") "lean er" "fast er" "strong er" #d'oh> paste(adjectives,"er",sep="") "leaner" "faster" "stronger"Empty vectors get an undeserved first class treatment: > paste(indelPositions,"i",sep="") "i"> indelPositions> paste(indelPositions,"i",sep="") "5i"...

useR! 2011 – Brandon Whitcher: Quantitative Medical Image Analysis

October 31, 2011
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useR2011 – Whitcher View more presentations from rusersla

R 2.14.0 is released

October 31, 2011
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As scheduled, the first release of the new R 2.14 series is now available for download in source code form. As of this writing, pre-compiled binaries for Windows, Linux and MacOS aren't yet available, but will appear on your local CRAN mirror in the next couple of days. One of the biggest changes in 2.14 is the introduction of...

useR! 2011 – Lee E. Edlefsen: Scalable Data Analysis in R

October 31, 2011
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useR2011 – Edlefsen View more presentations from rusersla

useR! 2011 – Ulrike Grömping: Design of Experiments

October 31, 2011
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useR2011 – Gromping View more presentations from rusersla

Simulation: Efficiency of mean with median Goal: Show the…

October 31, 2011
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Simulation: Efficiency of mean with median Goal: Show the efficiency of the mean when compared with the median using a large simulation where both estimators are applied on a sample of U(0,1) uniformly distributed random numbers. Input: # Goal: Show...

Last chance to enter the \$20,000 "Applications of R" contest

October 31, 2011
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Don't forget that midnight tonight (Pacific Daylight Time) is the deadline to submit your draft entry for the Applications of R in Business Contest, with \$20,000 in prizes up for grabs from Revolution Analytics. You'll still be able to edit your entry during the public review period (until November 30), but no new entries will be accepted for the...

Multivariate linear mixed models: livin’ la vida loca

October 31, 2011
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I swear there was a point in writing an introduction to covariance structures: now we can start joining all sort of analyses using very similar notation. In a previous post I described simple (even simplistic) models for a single response … Continue reading →

Example 9.12: simpler ways to carry out permutation tests

October 31, 2011
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In a previous entry, as well as section 2.4.3 of the book, we describe how to carry out a 2 group permutation test in SAS as well as with the coin package in R. We demonstrate with comparing the ages of the female and male subjects in the HELP study.I...

R 2.14.0 is released!

October 31, 2011
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The new R 2.14.0 is out! Get the source code from here. Take a look at these posts for some miscellaneous advices to make the upgrade easier. Also this thread on stackoverflow and this post contributed by Tal Galili&nbs...

Batman Equation Happy Halloween! Plot the Batman logo in…

October 31, 2011
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Batman Equation Happy Halloween! Plot the Batman logo in CloudStat with the legendary Batman Equation.

Power Tools for Aspiring Data Journalists: R

October 31, 2011
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Picking up on Paul Bradshaw’s post A quick exercise for aspiring data journalists which hints at how you can use Google Spreadsheets to grab – and explore – a mortality dataset highlighted by Ben Goldacre in DIY statistical analysis: experience the thrill of touching real data, I thought I’d describe a quick way of analysing