ravi : I appreciate your help but could you be a little more specific about what you mean ? I can just stack aggfxdata below the current full one ( the rbind works out the ordrering by date because it's a zoo object ) so it's not a question of where to put the new one. It's a question of how to avoid rbind ? I apologize because I don't think I understand what you are saying. Or maybe it's not possible to avoid rbind ? Thanks.
-----Original Message----- From: Ravi Varadhan [mailto:[EMAIL PROTECTED] Sent: Friday, December 08, 2006 5:21 PM To: Leeds, Mark (IED); r-help@stat.math.ethz.ch Subject: RE: [R] any way to make the code more efficient ? Using "rbind" almost always slows things down significantly. You should define the objects "aggfxdata" and "fullaggfxdata" before the loop and then assign appropriate values to the corresponding rows and/or columns. Ravi. ------------------------------------------------------------------------ ---- ------- Ravi Varadhan, Ph.D. Assistant Professor, The Center on Aging and Health Division of Geriatric Medicine and Gerontology Johns Hopkins University Ph: (410) 502-2619 Fax: (410) 614-9625 Email: [EMAIL PROTECTED] Webpage: http://www.jhsph.edu/agingandhealth/People/Faculty/Varadhan.html ------------------------------------------------------------------------ ---- -------- -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Leeds, Mark (IED) Sent: Friday, December 08, 2006 4:17 PM To: r-help@stat.math.ethz.ch Subject: [R] any way to make the code more efficient ? The code bekow works so this is why I didn't include the data to reproduce it. The loops about 500 times and each time, a zoo object with 1400 rows and 4 columns gets created. ( the rows represent minutes so each file is one day worth of data). Inside the loop, I keep rbinding the newly created zoo object to the current zoo object so that it gets bigger and bigger over time. Eventually, the new zoo object, fullaggfxdata, containing all the days of data is created. I was just wondering if there is a more efficient way of doing this. I do know the number of times the loop will be done at the beginning so maybe creating the a matrix or data frame at the beginning and putting the daily ones in something like that would Make it be faster. But, the proboem with this is I eventually do need a zoo object. I ask this question because at around the 250 mark of the loop, things start to slow down significiantly and I think I remember reading somewhere that doing an rbind of something to itself is not a good idea. Thanks. #======================================================================= =============================================== start<-1 for (filecounter in (1:length(datafilenames))) { print(paste("File Counter = ", filecounter)) datafile= paste(datadir,"/",datafilenames[filecounter],sep="") aggfxdata<-clnaggcompcurrencyfile(fxfile=datafile,aggminutes=aggminutes, fillholes=1) logbidask<-log(aggfxdata[,"bidask"]) aggfxdata<-cbind(aggfxdata,logbidask) if ( start == 1 ) { fullaggfxdata<-aggfxdata start<-0 } else { fullaggfxdata<-rbind(fullaggfxdata,aggfxdata) } } #======================================================================= ================================== -------------------------------------------------------- This is not an offer (or solicitation of an offer) to buy/se...{{dropped}} ______________________________________________ R-help@stat.math.ethz.ch 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. -------------------------------------------------------- This is not an offer (or solicitation of an offer) to buy/se...{{dropped}} ______________________________________________ R-help@stat.math.ethz.ch 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.