Who interacts on Twitter during a conference (#JDSLille)

June 7, 2015
By
Who interacts on Twitter during a conference (#JDSLille)

Disclamer: This is a joint post with Avner Bar-Hen, a.k.a. @a_bh, Benjamin Guedj, a.k.a. @bguedj and Nathalie Villa, a.k.a. @Natty_V2 Organised annually since 1970 by the French Society of Statistics (SFdS), the Journées de Statistique (JdS) are the most important scientific event of the French statistical community. More than 400 researchers, teachers and practitioners meet at each edition. In 2015,...

Read more »

European debt and interest

June 7, 2015
By
European debt and interest

I was told the Eurostat package would be interesting for me.  This is indeed true and now I want to use it to plot some data which are related core of some of the European policies; debt.In these plots I only show individual countries, not aggrega...

Read more »

Aggregate player preference for the first 20 building created in Illyriad

June 6, 2015
By

I was at the Microsoft Gaming data hackathon today. Gaming is very big business and companies rarely publish detailed game data. Through contacts one of the organizers was able to obtain two gaming datasets, both containing just under 300M of compressed of data. Illyriad supplied a random snapshot of anonymised data on 50,000 users and

Read more »

ogdindiar: R package to easily access Open Government Data from India Portal

June 6, 2015
By

Following up on my earlier posts on accessing Open Government Data from R, I've wrapped this code into an R package - ogdindiar. It's available on GitHub at https://github.com/steadyfish/ogdindiarIt provides one simple function - fetch_data()&nbsp...

Read more »

A Better ZigZag

June 6, 2015
By
A Better ZigZag

There are a lot of “winning” strategies for bull markets floating around. “Buy the pullbacks” is certainly one of them. Does this sound simple enough to implement to you? While I am no Sheldon Cooper (although I have a favorite couch seat), I still like to live in a somewhat well defined world, a world The post

Read more »

IPython Markdown Opportunities in IPython Notebooks and Rstudio

June 6, 2015
By
IPython Markdown Opportunities in IPython Notebooks and Rstudio

One of the reasons I started working on the Wrangling F1 Data With R book was to see what the Rmd (RMarkdown) workflow was like. Rmd allows you to combine markdown and R code in the same document, as well as executing the code blocks and then displaying the results of that code execution inline

Read more »

RcppArmadillo 0.5.200.1.0

Conrad put out a new minor release 5.200.1 of Armadillo yesterday. Armadillo is a powerful and expressive C++ template library for linear algebra aiming towards a good balance between speed and ease of use with a syntax deliberately close to a Matlab. Our corresponding RcppArmadillo release 0.5.200.1.0 is now on CRAN and on its way into...

Read more »

PERFORMANCE: Calling R_CheckUserInterrupt() every 256 iteration is actually faster than ever 1,000,000 iteration

June 5, 2015
By
PERFORMANCE: Calling R_CheckUserInterrupt() every 256 iteration is actually faster than ever 1,000,000 iteration

If your native code takes more than a few seconds to finish, it is a nice courtesy to the user to check for user interrupts (Ctrl-C) once in a while, say, every 1,000 or 1,000,000 iteration. The C-level API of R provides R_CheckUserInterrupt() for this (see 'Writing R Extensions' for more information on this function). Here's what...

Read more »

Any R code as a cloud service: R demonstration at BUILD

June 5, 2015
By
Any R code as a cloud service: R demonstration at BUILD

At last month's BUILD conference for Microsoft developers in San Francisco, R was front-and-center on the keynote stage. In the keynote, Microsoft CVP Joseph Sirosh introduced the "language of data": open source R. Sirosh encouraged the audience to learn R, saying "if there is a single language that you choose to learn today .. let it be R". The...

Read more »

Momentum, Markowitz, and Solving Rank-Deficient Covariance Matrices — The Constrained Critical Line Algorithm

June 5, 2015
By
Momentum, Markowitz, and Solving Rank-Deficient Covariance Matrices — The Constrained Critical Line Algorithm

This post will feature the differences in the implementation of my constrained critical line algorithm with that of Dr. Clarence … Continue reading →

Read more »

New package for image processing in R

June 5, 2015
By
New package for image processing in R

I’ve written a package for image processing in R, with the goal of providing a fast API in R that lets you do things in C++ if you need to. The package is called imager, and it’ on Github. The whole thing is based on CImg, a very nice C++ library for image processing by

Read more »

Macros in R

June 5, 2015
By
Macros in R

In programming, sometimes it’s useful to write a macro rather than a function. (Don’t worry if you’ve never heard the term before.) In this post, I’ll give an example of use of macros in R. using the gtools package on CRAN. I wanted to write some utility code to help me reuse my earlier R commands during … Continue reading...

Read more »

Beautiful table-outputs: Summarizing mixed effects models #rstats

June 4, 2015
By
Beautiful table-outputs: Summarizing mixed effects models #rstats

The current version 1.8.1 of my sjPlot package has two new functions to easily summarize mixed effects models as HTML-table: sjt.lmer and sjt.glmer. Both are very similar, so I focus on showing how to use sjt.lmer here. Linear mixed models summaries as HTML table The sjt.lmer function prints summaries of linear mixed models (fitted with

Read more »

A Practical Example of Calculating Padé Approximant Coefficients Using R

June 4, 2015
By
A Practical Example of Calculating Padé Approximant Coefficients Using R

Introduction I recently had the opportunity to use Padé approximants. There is a lot of good information available on line on the theory and applications of using Padé approximants, but I had trouble finding a good example explaining just how to calculate the co-efficients. Basic Background Hearken back to undergraduate calculus for a moment. For Read the full...

Read more »

Some Impressions from R Finance 2015

June 4, 2015
By
Some Impressions from R Finance 2015

by Joseph Rickert The R/Finance 2015 Conference wrapped up last Saturday at UIC. It has been seven years already, but R/Finance still has the magic! - mostly very high quality presentations and the opportunity to interact and talk shop with some of the most accomplished R developers, financial modelers and even a few industry legends such as Emanuel Derman...

Read more »

Can Bradley Wiggins Do It? Welcome to the Thunder-Drome!

June 4, 2015
By
Can Bradley Wiggins Do It? Welcome to the Thunder-Drome!

Many have tried. Most have failed.Bradley Wiggins knows this. He also knows the ordeal he faces, knows the pain he will endure and knows the scrutiny he will face. It's nothing he hasn't experienced before, having raced and won the world's most pr...

Read more »

Welcome to AriLamstein.com!

June 4, 2015
By
Welcome to AriLamstein.com!

Today I am happy to announce that I have migrated my blog from JustAnRBlog.wordpress.com to AriLamstein.com. I thought I would give an inside peek into the change in case others have an interest. Also, I would personally like to see more R packages and blogs, and I hope that this post can encourage others to

Read more »

R Recipe: RStudio and UNC Paths

June 4, 2015
By

RStudio does not like Uniform Naming Convention (UNC) paths. This can be a problem if, for example, you install it under Citrix. The solution is to create a suitable environment file. This is what worked for me: I created an .Renviron file in my Documents folder on the Citrix remote drive. The file had the The post

Read more »

New online R tutorial by DataCamp: Intermediate R programming

June 4, 2015
By
New online R tutorial by DataCamp: Intermediate R programming

Today the course creation team at DataCamp released a new online R tutorial called Intermediate R. It is the sequel to our infamous Introduction to R course that has been taken by over 60,000 R enthusiasts. This new tutorial combines short videos with in-browser coding exercises to increase your R knowledge even more. Start the new The post

Read more »

Processing Punycode and IDNA Domain Names in R

June 3, 2015
By

When fighting the good cyber-fight, one often has to process domain names. Our good friend @alexcpsec was in need of Punycode/IDNA processing in R which begat the newly-minted punycode R package. Much of the following has been culled from open documentation, so if you are already “in the know” about Punycode & IDNA, skip to the...

Read more »

Discovered Two Great Web Sites Today

June 3, 2015
By
Discovered Two Great Web Sites Today

Today is my lucky day.  I learned of two very interesting Web pages, both of them quite informative and the first of them rather provocative (yay!). I have some comments on both, in some cases consisting of mild disagreement, which I may post later, but in any event, I highly recommend both.  Here they are: … Continue reading...

Read more »

Computing with GPUs in R

June 3, 2015
By
Computing with GPUs in R

On Monday, we compared the performance of several different ways of calculating a distance matrix in R. Now there's another method to add to the list: using GPU acceleration in R. A GPU is a dedicated, high-performance chip available on many computers today. Unlike the CPU, it's not used for general computations, but rather for specialized tasks that benefit...

Read more »

My aversion to pipes

June 3, 2015
By

At the risk of coming across as even more of a curmudgeonly old fart than people already think I am, I really do dislike the current vogue in R that is the pipe family of binary operators; e.g. %>%. Introduced by Hadley Wickham and popularised and advanced via the magrittr package by Stefan Milton Bache, the basic idea...

Read more »

R vs Autobox vs ForecastPro vs …

June 2, 2015
By

Every now and then a commercial software vendor makes claims on social media about how their software is so much better than the forecast package for R, but no details are provided. There are lots of reasons why you might select a particular software solution, and R isn’t for everyone. But anyone claiming superiority should

Read more »

Auditing data transformation

June 2, 2015
By

Auditing data transformation can be simply described as gathering metadata about the transformation process. The most basics metadata would be a timestamp, atomic transformation description, data volume on input, data volume on output, time elapsed. If you work with R only interactively you may find it more like a fancy tool. On the other hand for automated scheduled...

Read more »

New package commonmark: yet another markdown parser?

June 2, 2015
By
New package commonmark: yet another markdown parser?

Last week the commonmark package was released on CRAN. The package implements some very thin R bindings to John Macfarlane’s (author of pandoc) cmark library. From the cmark readme: cmark is the C reference implementation of CommonMark, a rationalized version of Markdown syntax with a spec. It provides a shared library...

Read more »

Air Pollution (PM10 and PM2.5) in Different Cities using Interactive Charts

June 2, 2015
By

Gardiner Harris, who is a South Asia correspondent of the New York Times, shared a personal story of his son’s breathing troubles in New Delhi, India, in a recent dispatch titled Holding Your Breath in India. In this post, I use data from the World Health Organization’s Website to identify and map cities where the air quality is...

Read more »

Hacks for thinking about high-dimensional space

June 2, 2015
By
Hacks for thinking about high-dimensional space

High-dimensional Euclidean space is ℝ×ℝ×ℝ×ℝ×ℝ×…. Cartesian product of many continuous quantities. You are already familiar with the concept via “an arbitrary...

Read more »

Using Azure as an R datasource: Part 2 – Pulling data from MySQL/MariaDB

June 2, 2015
By
Using Azure as an R datasource: Part 2 – Pulling data from MySQL/MariaDB

by Gregory Vandenbrouck Software Engineer, Mirosoft This post is the second in a series that covers pulling data from various Windows Azure hosted storage solutions (such as MySQL, or Microsoft SQL Server) to an R client on Windows or Linux. Last time we covered pulling data from SQL Azure to an R client on Windows. This time we’ll be...

Read more »