Following on from my previous post about Near Earth Objects, today we are going to solve Kepler’s Equation to find the eccentric anomaly, which is the next step towards plotting the positions of these NEOs relative to Earth. The Eccentric, True and Mean Anomalies The relationship between the eccentric ... [Read more...]

AND I HAVE A GREAT REJOICING DAY (mnemonic rule generated by mnemoneitoR for first 7 digits of Pi according to The Wonderful Wizard Of Oz) Is there some number impossible to memorize? Do not worry, here comes mnemoneitoR: the tool that you was always looking for! With mnemoneitoR you can translate ... [Read more...]

      My system is 64-bit centOS 6.5. The 64-bit version then is 0.98.766 and the following error  appeared when installing RStudio Server preview version: Refer to an article on stackoverflow: Completion of the above steps is still not enough. Running rstudio-server verify-installation still reports errors. The problem lies in the lack of library... ... [Read more...]

In Part 1 of this series we moved the first steps into building our Sales Dashboard in R. In this Part 2 we explore additional ways to display sales related data. If you haven't read Part 1, it is highly … Continue reading → [Read more...]

Today’s email question: I work within a government budget office and sometimes have to forecast fairly simple time series several quarters into the future. Auto.arima() works great and I often get something along the lines of: ARIMA(0,0,1)(1,1,0)[12] with drift as the lowest AICc. However, my boss (who does ... [Read more...]

The Orange County R User Group (OC-RUG) will soon host a free webinar on the new “RSelenium” R Package which provides a set of R bindings for the Selenium 2.0 [Read more...]

In a new article for FastCoLabs, journalist Tina Amirtha has published a follow-up article to last month's piece on R's impact on open science. In her latest article, the focus is on how R is used at companies and displacing legacy statistics software like SAS: SAS is no match for ... [Read more...]

The dams package provides functionality to access over 74,000 dams in the National Inventory of Dams (NID) from the US Army Corps of Engineers, the single largest source of dams in the United States. Each dam has 64 attributes such as geographical... [Read more...]

Last night I was working on a talk on creating effective graphs. Mostly, I needed to update the colors, as there’d been some gaudy ones in its previous form (e.g., slide 22). I usually pick colors using the crayons in the Mac Color Picker. But that has just 40 crayons, ... [Read more...]

I'll be doing a morning tutorial at useR! at the end of June in Los Angeles. I've done this same presentation at the last few conferences and this will probably be the last time for this specific workshop. I will be including a copy of the book for ... [Read more...]

The Euclid Algorithm provides a solution to the greatest common divisor (GCD) of two natural numbers $x_{1}$ and $x_{-2}$, denoted by $GCD(x_{1}, x_{2})$. This will produce the largest integer that divides $x_{1}$ and $x_{2}$. Solution is proposed by ... [Read more...]

Having a habit of compulsively wondering approximately every 34.765th day about how zip compression (bzip2 in this case) might be used to measure information contained in data – this time the question popped up in my head of whether or … Continue reading → [Read more...]

In a recent post on the DataColada blog, Uri Simonsohn wrote about “We cannot afford to study effect size in the lab“. The central message is: If we want accurate effect size (ES) estimates, we need large sample sizes (he suggests four-digit n’s). As this is hardly possible in ... [Read more...]

I admit it looks like I am the only person in the world who has not read Michael Lewis’  Flash Boys. I was more attracted to this fine paper with slightly fewer views than Flash Boys. Baron, Matthew and Brogaard, Jonathan and Kirilenko, Andrei A.... [Read more...]

A bug-fix release 0.3.2.1.2 is of RcppEigen is now on CRAN and in Debian. It contains a short upstream patch by Gaek Guennebaud for the UBSAN warnings that were flagged at CRAN (from a rather harmless cpu-id comparison). The NEWS entry follows. ... [Read more...]

Today, I want to follow up with the Calendar Strategy: Option Expiry post. Let’s examine the importance of the FED meeting days as presented in the Fed Days And Intermediate-Term Highs post. Let’s dive in and examine historical perfromance of SPY during FED meeting days: Please note 100 day ... [Read more...]

So day 2 of the #JHUSMARTHack was last week, but I figured this would be a good time to discuss what was accomplished. I created some packages that are somewhat specialized and aren't fully finished yet, so I'll hold off. What I really want to discuss though is why I like ... [Read more...]

I’ve struggled all morning on how to set shapefile encodings in R. Finally I got this solution to handle both French and Spanish characters. Happy coding! The post How to merge a shapefile and set the encoding with R appeared first on Jose Gonzalez. [Read more...]

I’m frequently asked by newcomers to R to provide an easy to follow generic set of instructions on how to download data, transform it, aggregate it, make graphs, and write it all up for publication in a high impact journal – all by the end of the day ! While such ... [Read more...]

by Seth Mottaghinejad, Analytic Consultant for Revolution Analytics In the last article, we showed two separate R implementations of the Collatz conjecture: 'nonvec_collatz' and 'vec_collatz', with the latter being more efficient than the former because of the way it takes advantage of vectorization in R. Let's once again ... [Read more...]