Dear friend, In an R program running permanently on a server I would like to read hour by hour the temperature in *C and the humidity from a site like this (actually, from many of such sites): http://www.wunderground.com/global/stations/16239.html How can I read the content of the site and select the info I need? Ciao Vittorio
Of course you could use readLines() and post process by using appropriate functions such as grep(), strsplit() and friends later on. Uwe Ligges vittorio wrote:> Dear friend, > > In an R program running permanently on a server I would like to read hour by > hour the temperature in *C and the humidity from a site like this (actually, > from many of such sites): > > http://www.wunderground.com/global/stations/16239.html > > How can I read the content of the site and select the info I need? > > Ciao > Vittorio > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code.
Nutter, Benjamin
2008-Jun-05 20:45 UTC
[R] [Possible SPAM] Reading selected lines in an .html file
I've tried to tackle a similar question at the request of a coworker. Unfortunately, it is difficult to read in HTML code because it lacks character that can consistently be used as a delimiter. The only guideline I can offer is that any text you're interested in is going to be between a ">" and a "<". So the goal is to eliminate anything between < and >. What's more, if you really want to read in HTML code, you'll need a good grasp on HTML itself, and some familiarity with how the code you're reading in is structured. For instance, I'm attaching code that I wrote to read in HTML tables that were generated by other functions commonly used in my work place. But my code assumes that the tables are written by row (using the <tr> tag. Essentially, after studying the code I was going to read in, I hand picked the markers that I could use to isolate the text I wanted. I then proceeded to play a game of Simon Says to break down the code to smaller and smaller pieces until I got what I wanted. Unless you're going to be doing this a lot, I wouldn't recommend taking the time to try and write a function like this. In most cases it's probably faster just to copy the data by hand. But if you are determined to make it work, I hope the ideas help. Benjamin -----Original Message----- From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf Of vittorio Sent: Wednesday, June 04, 2008 3:50 PM To: r-help at stat.math.ethz.ch Subject: [Possible SPAM] [R] Reading selected lines in an .html file Dear friend, In an R program running permanently on a server I would like to read hour by hour the temperature in *C and the humidity from a site like this (actually, from many of such sites): http://www.wunderground.com/global/stations/16239.html How can I read the content of the site and select the info I need? Ciao Vittorio ______________________________________________ R-help at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. ================================== P Please consider the environment before printing this e-mail Cleveland Clinic is ranked one of the top hospitals in America by U.S. News & World Report (2007). Visit us online at http://www.clevelandclinic.org for a complete listing of our services, staff and locations. Confidentiality Note: This message is intended for use only by the individual or entity to which it is addressed and may contain information that is privileged, confidential, and exempt from disclosure under applicable law. If the reader of this message is not the intended recipient or the employee or agent responsible for delivering the message to the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this communication in error, please contact the sender immediately and destroy the material in its entirety, whether electronic or hard copy. Thank you.