Hi all, I am trying to download some tab separated data from the internet. The data is not available directly at the URL that could be known apriori. There is an intermediate form where start and end dates have to be given to get to the required page.
For example, I want to download data for a station 03015795. The form for this station is at: http://ida.water.usgs.gov/ida/available_records.cfm?sn=03015795 I could get the start date and end date from this form using: # # Specifying station and reading from the opening form stn<-"03015795" myurl<-paste("http://ida.water.usgs.gov/ida/available_records.cfm?sn=",stn,sep="";) mypage1 = readLines(myurl) # Getting the start and end dates mypattern = '<td align="center">([^<]*)</td>' datalines = grep(mypattern, mypage1[124], value=TRUE) getexpr = function(s,g)substring(s,g,g+attr(g,'match.length')-1) gg = gregexpr(mypattern, datalines) matches = mapply(getexpr,datalines,gg) result = gsub(mypattern,'\\1',matches) names(result)=NULL mydates<-result[1:2] I want to know how I can feed these start and end dates to the form and execute the button to go to the data page and then to download the data, either as displayed in the browser or by saving as a file. Any help on this is most appreciated. Thanks. HC -- View this message in context: http://r.789695.n4.nabble.com/Downloading-tab-separated-data-from-internet-tp4152318p4152318.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@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.
