## 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

October 31, 2011
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## Risk parity

October 31, 2011
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Some thoughts and resources regarding a popular fund management buzzword. The idea Given asset categories (like stocks, bonds and commodities) create a portfolio where each category contributes equally to the portfolio variance. Two operations There are two cases in creating a risk parity portfolio: the universe is the asset categories the universe is the assets … Continue reading...

## Sampling for Monte Carlo simulations with R

October 31, 2011
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$Sampling for Monte Carlo simulations with R$

I've knocked together a quick function for generating efficient Monte Carlo samples. It takes a bit of the legwork out of running Monte Carlo simulations.

## Using IUCN-Data, ArcMap 9.3 and R to Map Species Diversity

October 31, 2011
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..I'm overwhelmed by the ever-growing loads of data that's made available via the web. I.e., IUCN collects and hosts spatial species data which is free for download. I'm itching to play with all this data... And, in the end there may arise ...

## Reading Excel data is easy with JGR and XLConnect

October 30, 2011
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Despite the fact that Excel is the most widespread application for data manipulation and (perhaps) analysis, R's support for the xls and xlsx file formats has left a lot to be desired. Fortunately, the XLConnect package has been created to fill this void, and now JGR 1.7-8 includes integration with XLConnect package to load .xls

## Learning R: Project 1, Part 2

October 30, 2011
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So it's been a week since I started down this path.  I worked most of this out over last weekend, went to a conference, had hectic week at work, and then realized I lost my work.  Gah.I'll be posting my general thoughts on R later.  Most...

## Bayesian ideas and data analysis

October 30, 2011
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Here is another Bayesian textbook that appeared recently. I read it in the past few days and, despite my obvious biases and prejudices, I liked it very much! It has a lot in common (at least in spirit) with our Bayesian Core, which may explain why I feel so benevolent towards Bayesian ideas and

## The present and future of the R blogosphere (~7 minute video from useR2011)

October 30, 2011
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This is (roughly) the lightning talk I gave in useR2011. If you are a reader of R-bloggers.com then this talk is not likely to tell you anything new. However, if you have a friend, college or student who is a new useRs of R, this talk will offer him a decent introduction to what the R Read more...

## Modelling with R: part 5

October 30, 2011
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In our exercise of learning modelling in R, we have till now succeeded in doing the following:Importing the dataPreparing and transforming the dataRunning a logistic regressionCreating a decision treeSpecifically, we created a decision tree using the r...

## Proc report for simple statistics

October 30, 2011
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Ken Beath, of Macquarie University, commented on an earlier entry that the best way to generate summary statistics is using proc report. While the best tools might differ, depending on the purpose, we wanted to share Ken's code demonstrating how to re...

## Rcpp reverse dependency graph

October 30, 2011
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I played around with reverse dependencies of Rcpp. At the moment, 44 packages depend on Rcpp and the number goes up to 53 when counting recusive reverse dependencies. I've used graphviz for the representation of the directed graph Here is the c...

## Installing R 2.14.0 on an iBook G4 running Mac OS 10.4.11

October 30, 2011
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My 12" iBook G4 is celebrating its 8th birthday today! Time for a little present. How about R 2.14.0?The iBook is still in daily use, mostly for browsing the web, writing e-mails and this blog; and I still use it for R as well. For a long time it run R...

## Anarchy Golf! And that’s your Sunday gone.

October 29, 2011
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I like to follow good practice when I program. I want my code to be readable, properly indented, modular and re-usable. And I want my variables to have descriptive names. There’s nothing that I hate moderately dislike more than arbitrary … Continue reading →

## Plotting gain chart

October 29, 2011
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Gain chart is a popular method to visually inspect model performance in binary prediction. It presents the percentage of captured positive responses as a function of selected percentage of a sample. It is easy to obtain it using ROCR package plott...

## SabreR

October 29, 2011
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SabreR just released an update. It is another software package that can estimate multivariate multilevel model (other options are aML, MCMCglmm, etc.). They seem to also have a book dedicated to the software, which be worth checking out.It will be grea...

## Migrating from SPSS/Excel to R, Part 3: Preparing your Data

October 29, 2011
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In this post, I describe how to prepare your data for migrating between SPSS/Excel and R. This is the third …Continue reading »

## Dennis Ritchie 1941-2011

October 28, 2011
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I just got the “news” that Dennis Ritchie died, although this happened on October 12… The announcement was surprisingly missing from my information channels and certainly got little media coverage, compared with Steve Jobs‘ demise. (I did miss the obituaries in the New York Times and in the Guardian. The Economist has the most appropriate

## Comparison of ave, ddply and data.table

October 28, 2011
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This is a copy of a post by me on the R-statistics blog. Fortran and C programmers often say that interpreted languages like R are nice and all, but lack in terms of speed. How fast something works in R… See more ›

## New R User Group in Dublin, Ireland

October 28, 2011
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There have been several requests to an R User Group in Ireland, so thanks to Kevin O'Brien for stepping up to co-ordinate the Dublin-R group. Kevin invites all R users in the area to the first meeting on November 17: The Dublin R users group will be holding a series of monthly meetings. On the agenda is the development...

## My little presentation on getting web data through R

October 28, 2011
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With examples from rOpenSci R packages. p.s. I am no expert at this...Web data from R View more presentations from schamber

## R-TreeBASE Tutorial

October 28, 2011
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My treebase package is now up on the CRAN repository. (Source code is up, the binaries should appear soon). Here’s a few introductory examples to illustrate some of the functionality of the package. Thanks in part to new data deposition … Continue reading →

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