2799 search results for "Twitter"

art brut

November 12, 2011
By
art brut

Filed under: pictures, R Tagged: Le Monde, mathematical puzzle, R

Read more »

Web Scraping Google+ via XPath

November 11, 2011
By
Web Scraping Google+ via XPath

Google+ just opened up to allow brands, groups, and organizations to create their very own public Pages on the site. This didn’t bother me to much but I’ve been hearing a lot about Google+ lately so figured it might be fun to set up an XPath scraper to extract information from each post of a status

Read more »

The Marriage of Hadoop and R: Revolution Analytics at Hadoop World

November 11, 2011
By
The Marriage of Hadoop and R: Revolution Analytics at Hadoop World

Revolution Analytics CTO David Champagne visited Hadoop World 2011 this week, and delivered a presentation on "The Powerful Marriage of R and Hadoop" to a standing-room-only crowd of R and Hadoop enthusiasts. I've included David's slides below: The talk also generated praise on Twitter, for example: David was also interviewed by The Cube during the conference. In the video...

Read more »

Resampling and Shrinkage : Solutions to Instability of mean-variance efficient portfolios

November 11, 2011
By
Resampling and Shrinkage : Solutions to Instability of mean-variance efficient portfolios

Small changes in the input assumptions often lead to very different efficient portfolios constructed with mean-variance optimization. I will discuss Resampling and Covariance Shrinkage Estimator – two common techniques to make portfolios in the mean-variance efficient frontier more diversified and immune to small changes in the input assumptions. Resampling was introduced by Michaud in Efficient

Read more »

Web Scraping Yahoo Search Page via XPath

November 10, 2011
By
Web Scraping Yahoo Search Page via XPath

Seeing as I’m on a bit of an XPath kick as of late, I figured I’d continue on scraping search results but this time from Yahoo.com Rolling my own version of xpathSApply to handle NULL elements seems to have done the trick and so far it’s been relatively easy to do the scraping. I’ve created

Read more »

In case you missed it: October Roundup

November 10, 2011
By

In case you missed them, here are some articles from October of particular interest to R users. The creator of the ggplot2 package, Hadley Wickham, shares details on some forthcoming big-data graphics functions (based on research sponsored by Revolution Analytics). A list of several dozen free data sources that can easily be imported into R. Bob Muenchen gave a...

Read more »

Facebook Graph API Explorer with R

November 10, 2011
By
Facebook Graph API Explorer with R

I wanted to play around with the Facebook Graph API  using the Graph API Explorer page as a coding exercise. This facility allows one to use the API with a temporary authorisation token. Now, I don’t know how to make an R package for the proper API where you have to register for an API key and

Read more »

Diagram for a Bernoulli process (using R)

November 10, 2011
By
Diagram for a Bernoulli process (using R)

A Bernoulli process is a sequence of Bernoulli trials (the realization of n binary random variables), taking two values (0/1, Heads/Tails, Boy/Girl, etc…). It is often used in teaching introductory probability/statistics classes about the binomial distribution. When visualizing a Bernoulli process, it is common to use a binary tree diagram in order to show the Read more...

Read more »

Geometric Efficient Frontier

November 9, 2011
By
Geometric Efficient Frontier

What is important for an investor? The rate of return is at the top of the list. Does the expected rate of return shown on the mean-variance efficient frontier paints the full picture? If investor’s investment horizon is longer than one period, for example 5 years, than the true measure of portfolio performance is Geometric

Read more »

Web Scraping Google Scholar: Part 2 (Complete Success)

November 8, 2011
By
Web Scraping Google Scholar: Part 2 (Complete Success)

This is a followup to a post I uploaded earlier today about web scraping data off Google Scholar. In that post I was frustrated because I’m not smart enough to use xpathSApply to get the kind of results I wanted. However fast-forward to the evening whilst having dinner with a friend, as a passing remark,

Read more »

Sponsors

Never miss an update!
Subscribe to R-bloggers to receive
e-mails with the latest R posts.
(You will not see this message again.)

Click here to close (This popup will not appear again)