Successive Differences of a Randomly-Generated Timeseries

November 25, 2012
By

I was wondering about the null distribution of successive differences of random sequences, and decided to do some numerical experiments. I quickly realized that successive differences equates to taking successively higher-order numerical derivatives, ...

Read more »

Hello world!

November 25, 2012
By
Hello world!

Welcome to WordPress.com! This is your very first post. Click the Edit link to modify or delete it, or start a new post. If you like, use this post to tell readers why you started this blog and what you plan to do with it. Happy blogging!Filed under: U...

Read more »

Modis R: Package tutorial

November 24, 2012
By
Modis R: Package tutorial

The MODIS package for R For people who work in GIS in R there has been a bit of challenge in working with data from  Modis. I’ll use an example from my own work on UHI to illustrate. A while back I decided that I wanted to look at albedo data from MODIS.  If you

Read more »

Run R Code Within Python On The Fly

November 24, 2012
By
Run R Code Within Python On The Fly

Below is an example showing how to run R code within python, which is an extremely attractive feature for hardcore R programmers.

Read more »

Simulating weak gravitational lensing

November 24, 2012
By
Simulating weak gravitational lensing

In the search for dark matter, I have been having mixed success. It seems that locating DM in single halo skies is a fairly straightforward problem. However, when there are more than one halo, things get quite a bit trickier. As I have advocated many times before, including here and here, simulation can provide deep

Read more »

Personal CRAN-repository

November 24, 2012
By
Personal CRAN-repository

Offering - the backbone of open source. The image is CC by TenthMusePhotography This is part II of the previous package creation post. I've created my own CRAN repository since I wanted a quick upload. Perhaps in the future I'll post on the main server but right now...

Read more »

Secret Santa – unfinished business

November 24, 2012
By

Last week I wrote:This is actually a more difficult calculation (or I forgot too much probability). Luckily a bit of brute force comes in handy. To reiterate, in general simulated data shows 0.54 redraws because of the first person etc.colSums(countsto...

Read more »

ESSA2013 Conference

November 24, 2012
By
ESSA2013 Conference

It has been just announced that during ESSA2013 conference I am planning to organize a special track on "Statistical analysis of simulation models". I hope to get some presentations using GNU R to promote it in social simulation community.It is obvious that GNU R excels in analysis of simulation data. However, very often it can be neatly...

Read more »

A Light Touch on RPy2

November 23, 2012
By
A Light Touch on RPy2

For a statistical analyst, the first step to start a data analysis project is to import the data into the program and then to screen the descriptive statistics of the data. In python, we can easily do so with pandas package. Tonight, I’d like to add some spice to my python learning experience and do

Read more »

R is (Almost) Platform Independent

November 23, 2012
By

I write R scripts on both my laptop and desktop, so the main issue I have is making sure that the R scripts are updated on these devices. There are several ways to ensure this happens:Use a version control system (on the cloud), e.g GithubWrite R scrip...

Read more »

Shootout 2012 : first PLS regressions

November 23, 2012
By
Shootout 2012 : first PLS regressions

It´s time to start developing some regressions in order to find the best math treatment, the best number of terms, the best spectral regions, the best regression method,....This time I´m working with the PLS  package in R, and just to make ...

Read more »

Opting for shorter movies, be aware u might be cutting the entertainment too!

November 23, 2012
By
Opting for shorter movies, be aware u might be cutting the entertainment too!

Hello Friends,This time I thought to bring in little more spice and thought of focusing on movies.  I don’t know about you but I am a movie buff. Often on a weekend when I am trying to pick up a movie from my movie repository, which spans to some TBs now, I feel little lost.  Apart from a general...

Read more »

xts and GSOC 2012

November 23, 2012
By
xts and GSOC 2012

Josh Ulrich and Jeff Ryan mentored a Google Summer of Code (GSOC) project this summer focused on experimental functionality for xts in collaboration with R. Michael Weylandt, a student in operations research and financial engineering from Princeton. You might recognize Michael from his presentation at R/Finance this year, where he gave a talk entitled “A

Read more »

ggplot2 Tutorial

November 23, 2012
By
ggplot2 Tutorial

Here is a link to a wonderful ggplot2 tutorial: http://www.ceb-institute.org/bbs/wp-content/uploads/2011/09/handout_ggplot2.pdf by R. Saccilotto and the Basel Institute for Clinical Epidemiology …Continue reading »

Read more »

IPython vs knitr, or Python vs R

November 23, 2012
By
IPython vs knitr, or Python vs R

I watched this video by Fernando Pérez a few days ago when I was reading a comment by James Correia Jr on Simply Statistics: This is absolutely a fantastic talk that I recommend everybody to watch (it is good in both the form and content). Not surprisingly, I started thinking ipython vs knitr. Corey Chivers said we could...

Read more »

project euler: problem 61

November 22, 2012
By

Triangle, square, pentagonal, hexagonal, heptagonal, and octagonal numbers are all figurate (polygonal) numbers and are generated by the following formulae: Triangle P3,n=n(n+1)/2 1, 3, 6, 10, 15, ... Square P4,n=n2 ...

Read more »

Escaping the simplex, part 1

November 22, 2012
By
Escaping the simplex, part 1

Before tackling the main subject, two quick notes:I did not post for quite a while in part because I followed the Coursera online course Introduction to Computational Finance and Financial Econometrics.  It was a nice refresher, extremely well pre...

Read more »

Peer-reviewed R packages?

November 22, 2012
By
Peer-reviewed R packages?

Dear R-Users, a question: I am the author of the ‘qpcR’ package. Within this, there is a function ‘propagate’ that does error propagation based on Monte Carlo Simulation, permutation-based confidence intervals and Taylor expansion. For the latter I recently implemented a second-order Taylor expansion term that can correct for nonlinearity. The formulas are quite complex

Read more »

nice ggplot intro tutorial. Just run the commands, about 6 pages…

November 22, 2012
By

nice ggplot intro tutorial. Just run the commands, about 6 pages = flexible 1-3 hours of learning, depending how much reading you want to pair it with by Ramon Saccilotto

Read more »

We NEED more data

November 22, 2012
By
We NEED more data

Email One of the historic difficulties of doing research on urban energy systems has been the limited availability of data at sufficiently detailed spatial resolutions. Without this data, you might end up relying on aggregate information about the built environment, building occupants, and local geography that doesn't apply to the specifics of a particular neighbourhood

Read more »

Washington Gave Thanks To R:

November 22, 2012
By
Washington Gave Thanks To R:

The folks over at is.R() brought along an "adorable Turkey". I guess we'll thank them for their gift - and pardon the Turkey. Personally I thank them for a bucket of hints and tricks I freely used and will continue to do so.Tal brought us a great ...

Read more »

Connecting R to an Oracle database with RJDBC

November 22, 2012
By

In many circumstances, you might want to connect R directly to a database to store and retrieve data.  If the source database is an Oracle database, you have a number of options: ROracle RODBC RJDBC   Using ROracle should theoretically… Read more ›

Read more »

Controlling heatmap colors with ggplot2

November 22, 2012
By
Controlling heatmap colors with ggplot2

One of the most popular posts on this blog is the very first one, solving the issue of mapping certain ranges of values to particular colors in heatmaps. Given the abundance of ggplot2 usage in R plotting, I thought I’d … Continue reading →

Read more »

Happy Thanksgiving from is.R()!

November 22, 2012
By
Happy Thanksgiving from is.R()!

Today’s post is mostly to wish everyone a Happy Thanksgiving. We will be taking the rest of the week off, and will return on Monday. Below is some code to reproduce the adorable Turkey above; enjoy! https://gist.github.com/4122464

Read more »

Extending Commodity time series

November 21, 2012
By
Extending Commodity time series

I want to follow up with Extending Gold time series post by showing how we can extend Commodity time series. Most Commodity ETFs began trading in 2006, please see the List of Commodity ETFs page. I will use DBC – PowerShares DB Commodity Fund, one on the most liquid Commodity ETFs as my proxy for

Read more »

What’s the difference between POSIXct and POSIXlt?

November 21, 2012
By

POSIXct is the signed number of seconds since “the epoch”. For example it was 1351298112 UTC (GMT) when I wrote this. (1351298112 UTC = Sat Oct 27, 2:35 am GMT = Fri Oct 26, 8:35 pm EST = Fri Oct 26, 5:35 pm PST = 2:35 pm HST) POSIXlt is one of many text | character | string formats such as: May 17, 2017 17/5/2017 17-5-17 05:24:39

Read more »

Data types, part 3: Factors!

November 21, 2012
By
Data types, part 3: Factors!

In this third part of the data types series, I'll go an important class that I skipped over so far: factors.Factors are categorical variables that are super useful in summary statistics, plots, and regressions. They basically act like dummy variables t...

Read more »

Upcoming Webinar: Real-time, big-data analytics

November 21, 2012
By

A quick heads-up that I'll be presenting another brand-new webinar on Thursday next week (November 29). In Real-time Big Data Analytics: From Deployment to Production, I'll review the process of making predictive models work in real-live operational environments. I'll also tackle those ubiquitous buzz-words "real-time" and "big data", and the fact that they can mean very different things in...

Read more »

IPython vs RStudio+knitr

November 21, 2012
By
IPython vs RStudio+knitr

At a meeting last night with some collaborators at the Vélobstacles project, I was excitedly told about the magic of IPython and it’s notebook functionality for reproducible research. This sounds familiar, I thought to myself. Using a literate programming approach to integrate computation with the communication of methodology and results has been at the core

Read more »

Sponsors

Mango solutions



RStudio homepage



Zero Inflated Models and Generalized Linear Mixed Models with R

Dommino data lab

Quantide: statistical consulting and training



http://www.eoda.de





ODSC

ODSC

CRC R books series





Six Sigma Online Training





Contact us if you wish to help support R-bloggers, and place your banner here.