background preloader

R codeline_2

Facebook Twitter

Example .  An example of nested downloads using RCurl. This example uses RCurl to download an HTML document and then collect the name of each link within that document.

Example .  An example of nested downloads using RCurl.

The purpose of the example is to illustrate how we can combine the RCurl package to download a document and use this directly within the XML (or HTML) parser without having the entire content of the document in memory. We start the download and pass a function to the xmlEventParse() function for processing. As that XML parser needs more input, it fetches more data from the HTTP response stream. This is useful for handling very large data that is returned from Web queries. To do this, we need to use the multi interface for libcurl in order to have asynchronous or non-blocking downloading of the document. The remaining part is how we combine these pieces with RCurl and the XML packages to do the parsing in this asynchronous, interleaved manner.

The steps in the code are as explained as follows. Perform = FALSE . Algorithmic Trading with IBrokers. Kyle Matoba is a Finance PhD student at the UCLA Anderson School of Management.

Algorithmic Trading with IBrokers

He gave a presentation on Algorithmic Trading with R and IBrokers at a recent meeting of the Los Angeles R User Group. The discussion of IBrokers begins near the 12-minute mark. To leave a comment for the author, please follow the link and comment on his blog: FOSS Trading. Models Collecting Dust? How to Transform Your Results from Interesting to Impactful. Leading expert James Taylor, author of Decision Management Systems: A Practical Guide to Business Rules and Predictive Analytics, has developed a practical approach you can use to improve adoption and elevate your organization.

Models Collecting Dust? How to Transform Your Results from Interesting to Impactful

In this webinar, James will show you proven framework for putting predictive analytics to work: How to begin model-building with the decision in mind to establish consensus with business process owners;Proven ways to tie decisions to organizations, metrics, systems and business processes and;Pitfalls that prevent success and how to avoid them. Join this webinar to increase your team’s value to the organization and come away with an approach that ensures buy in from the beginning of the process through the implementation of recommendations. Pretty R syntax highlighter. R - What is the difference between gc() and rm() First, it is important to note that the two are very different in that gc does not delete any variables that you are still using- it only frees up the memory for ones that you no longer have access to (whether removed using rm() or, say, created in a function that has since returned).

r - What is the difference between gc() and rm()

Running gc() will never make you lose variables. The question of whether you should call gc() after calling rm(), though, is a good one. The documentation for gc helpfully notes: A call of gc causes a garbage collection to take place. This will also take place automatically without user intervention, and the primary purpose of calling gc is for the report on memory usage. So the answer is that it can be good to call gc() (and at the very least, can't hurt), even though it would likely be triggered anyway (if not right away, then soon). Memory Available for Data Storage. Description How R manages its workspace.

Memory Available for Data Storage

Details. Models Collecting Dust? How to Transform Your Results from Interesting to Impactful. Revolution R Enterprise 5.0 now available for free academic download. Revolution Analytics - Commercial Software & Support for the R Statistics Language. “Credit to whom credit is due” – Bloganalysen mit Google und R « LIBREAS.Library Ideas.

Angeregt vom wachsenden Interesse quantitativen Untersuchungen über die Wirkung von Bloginhalten, wie zuletzt im Beitrag Blogs als Quellen in der bibliothekarischen Fachkommunikation, lässt sich ebenfalls die Verlinkung innerhalb von Blogs näher explorieren.

“Credit to whom credit is due” – Bloganalysen mit Google und R « LIBREAS.Library Ideas

Um schnell an möglichen Daten zu gelangen, erscheint vielversprechend. Untitled. The Comprehensive Perl Archive Network - Extracting comments from a blog post with R. Note #1: Check out this very useful post by Najko Jahn describing how to extract links to blogs via Google Blog Search .

Extracting comments from a blog post with R

Note #2: I’ll update the code below once I find the time using Najko’s cleaner XPath-based solution. Recently I’ve been working with comments as part of the project on science blogging we’re doing at the Junior Researchers Group “Science and the Internet” . I wrote the script below to quickly extract comments from Atom feeds, such as those generated by . The code isn’t exactly pretty, mostly because I didn’t use an XML parser to properly read the data, instead resorting to brute-force pattern matching, but it gets the job done. HtmlToText(): Extracting Text from HTML via XPath. Converting HTML to plain text usually involves stripping out the HTML tags whilst preserving the most basic of formatting.

htmlToText(): Extracting Text from HTML via XPath

I wrote a function to do this which works as follows (code can be found on github): The above uses an XPath approach to achieve it’s goal. Another approach would be to use a regular expression. These two approaches are briefly discussed below: Regular Expressions One approach to achieving this is to use a smart regular expression which matches anything between “<” and “>” if it looks like a tag and rips it out e.g. GScholarXScraper: Hacking the GScholarScraper function with XPath. Kay Cichini recently wrote a word-cloud R function called GScholarScraper on his blog which when given a search string will scrape the associated search results returned by Google Scholar, across pages, and then produce a word-cloud visualisation.

GScholarXScraper: Hacking the GScholarScraper function with XPath

This was of interest to me because around the same time I posted an independent Google Scholar scraper function get_google_scholar_df() which does a similar job of the scraping part of Kay’s function using XPath (whereas he had used Regular Expressions). My function worked as follows: when given a Google Scholar URL it will extract as much information as it can from each search result on the URL webpage into different columns of a dataframe structure. In the comments of his blog post I figured it’d be fun to hack his function to provide an XPath alternative, GScholarXScraper.

I think that’s pretty much everything I added. JGR « Fells Stats. A GUI for R - Downloading And Installing Deducer. A Spatial Data Analysis GUI for R « Fells Stats. Eclipse IDE for R. Background: Eclipse is an open source Integrated Development Environment (IDE).

Eclipse IDE for R

As with Microsoft's Visual Studio product, Eclipse is programming language-agnostic and supports any language having a suitable plugin for the IDE platform. - development environment for R package developers. Free Development software downloads. Tinn-R Editor - GUI for R Language and Environment Read More The Tinn-R is an open source (GNU General Public License) and free project. It is an editor/word processor ASCII/UNICODE generic for the Windows operating system, very well integrated into the R, with characteristics of Graphical User Interface (GUI) and Integrated Development Environment (IDE). The project is coordinate by José Cláudio Faria/UESC/DCET. LANGUAGE: Object Pascal, IDE: DELPHI 2007. R-Extension. Web scraping - Extract Links from Webpage using R. The two posts below are great examples of different approaches of extracting data from websites and parsing it into R.

Scraping html tables into R data frames using the XML package. R - extracting node information. Current community your communities Sign up or log in to customize your list. more stack exchange communities Stack Exchange sign up log in tour help careers 2.0. Pretty R syntax highlighter. Pretty R syntax highlighter. Questions containing '[r] xml xpath' R - How do I scrape multiple pages with XML and ReadHTMLTable. Current community your communities Sign up or log in to customize your list. more stack exchange communities Stack Exchange sign up log in tour help careers 2.0 Stack Overflow Ask Question.

Xml - Web scraping with R over real estate ads. As an intern in an economic research team, I was given the task to find a way to automatically collect specific data on a real estate ad website, using R. I assume that the concerned packages are XML and RCurl, but my understanding of their work is very limited. Here is the main page of the website: Ideally, I'd like to construct my database so that each row corresponds to an ad. Here is the detail of an ad: My variables are: the price ("Prix"), the city ("Ville"), the surface ("surface"), the "GES, the "Classe énergie" and the number of room ("Pièces"), as well as the number of pictures shown in the ad.

I would also like to export the text in a character vector over which I would perform a text mining analysis later on. R preferred by Kaggle competitors. Kaggle, the predictive-analytics competition site, has analyzed the preferences of the 2,500 data scientists who participate in its competitions, and R was the most-preferred software of the competitors at 22.5%. The next-nearest alternative was Matlab, at 16%. On a related note, the premier of the Australian state of New South Wales has just launched a competition on Kaggle to predict the traffic on Sydney's M4 motorway. It's great to see government promoting the use of data analysis to solve (or at least better understand) civic problems, and this competition comes with some serious prizemoney: AUD$10,000 (about the same in $USD). Might be worth your time spending the Thanksgiving break doing a little modeling in R...

No Free Hunch: Profiling Kaggle’s user base To leave a comment for the author, please follow the link and comment on his blog: Revolutions. Blog-Reference-Functions/R at master · tonybreyal/Blog-Reference-Functions. Blog-Reference-Functions/R/googleScholarXScraper/googleScholarXScraper.R at master · tonybreyal/Blog-Reference-Functions. Facebook Graph API Explorer with R (on Windows) « Consistently Infrequent. Good GUI for R suitable for a beginner wanting to learn programming in R? - Statistical Analysis - Stack Exchange. GUI ! A Spatial Data Analysis GUI for R. I am excited to announce the addition of DeducerSpatial to the Deducer plug-in ecosystem. DeducerSpatial is a graphical user interface for the visualization and analysis of spatial data, built on Deducer's plug-in platform. R] Downloading data from from internet.

Web scraping. Sorenmacbeth/googleanalytics4r. R - How to transform XML data into a data.frame. Ordinarily, I would suggest trying the xmlToDataFrame() function, but I believe that this will actually be fairly tricky because it isn't well structured to begin with. Web Scraping Google Scholar (Partial Success) « Consistently Infrequent. Web Scraping Google Scholar: Part 2 (Complete Success) « Consistently Infrequent.

Comment faire pour transformer les données XML dans un data.frame? J'essaie d'apprendre R XML paquet. [BioC] PostForm() with KEGG. Blog-Reference-Functions/R/googlePlusXScraper/googlePlusXScraper.R at master · tonybreyal/Blog-Reference-Functions. Untitled. Untitled. Re: [R] Need help extracting info from XML file using XML package. Wacek Kusnierczyk wrote: > Don MacQueen wrote: >> I have an XML file that has within it the coordinates of some polygons >> that I would like to extract and use in R. The polygons are nested >> rather deeply. XML package help. Library(XML) url <- "

On research, visualization and productivity. Web Scraping Google Scholar (Partial Success) Web Scraping Google Scholar: Part 2 (Complete Success) When Venn diagrams are not enough – Visualizing overlapping data with Social Network Analysis in R. Untitled. A Short Introduction to the XML package for R. Memory Management in the the XML Package. The XML package. It's crantastic! Grabbing Tables in Webpages Using the XML Package. The Omega Project for Statistical Computing. RCurl. RStudio. Romain Francois, Professional R Enthusiast. R: Web Scraping R-bloggers Facebook Page « Consistently Infrequent. R: A Quick Scrape of Top Grossing Films from « Consistently Infrequent.

Untitled. [R] Need help extracting info from XML file using XML package from Don MacQueen on 2009-03-02 (R help archive) Package XML. CRAN - Package somplot.