I'm sorry but I see to be getting an error. > data.tmp <- aggregate(MyTo ~ Date + Hour, data = tUnitsort[, cols], max) > Error in `[.default`(xj, i) : invalid subscript type 'builtin'
________________________________ From: Rui Barradas [via R] <ml-node+s789695n463637...@n4.nabble.com> To: jcrosbie <ja...@crosb.ie> Sent: Thursday, July 12, 2012 3:12 PM Subject: Re: remove loop which compares row i to row i-1 Hello, I've not been following this thread but this seems ndependent from previous posts. Try the following. url <- "http://r.789695.n4.nabble.com/file/n4636337/BR3_2011_New.csv"; tUnitsort <- read.csv(url, header=TRUE) cols <- sapply(c("Date", "Hour", "BlockNumber", "MyTo"), function(x)      grep(x, names(tUnitsort))) # This does it # Use full data.frame 'tUnitsort' if you want data.tmp <- aggregate(MyTo ~ Date + Hour, data = tUnitsort[, cols], max) data.tmp <- merge(tUnitsort[, cols], data.tmp, by=c("Date", "Hour")) # Make it pretty idx <- grep("MyTo", names(data.tmp)) names(data.tmp)[idx] <- c("MyTo", "NewColumn") # See it head(data.tmp, 20) tail(data.tmp, 20) Also, you should quote the context. Many, almost all of us do NOT read the posts on Nabble. And Nabble does have a "quote" button. Hope this helps, Rui Barradas Em 12-07-2012 18:55, jcrosbie escreveu: > Thank you, > > I am sorry but I am still trying to figure out how to make the function > work. > > I have a column called tUnitsort$BlockNumber which can range from 0 to 6. > I have another two columns with the date and the hour ending for the given > day. > Example > > Date     Hour  BlockNumber  MyTo  NewColumn > 2011-01  1      2               140  >  140 > 2011-01  1      1              70   >   140 > 2011-01  1      0              0   >    140 > 2011-02  1      2              160   > 160 > 2011-02  1      1              70   >   160 > 2011-02  1      0              0   >    160 > 2011-03  1      2              150   > 150 > > I want to create a NewColumn which will place the MyTo number for the > highest block number for the rest blocks in a given hour ending within a > day. > > > ifelse(tUnitsort[,4]>=tUnitsort[-1,4],tUnitsort[,7],tUnitsort[-1,7]) > > I am unsure how to refference the element before in this case.  I thought > the -1 was doing this but I believe I'm wrong now. > > http://r.789695.n4.nabble.com/file/n4636337/BR3_2011_New.csv > BR3_2011_New.csv > > -- > View this message in context: > http://r.789695.n4.nabble.com/remove-loop-which-compares-row-i-to-row-i-1-tp4635327p4636337.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > [hidden email] 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. > ______________________________________________ [hidden email] 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. ________________________________ If you reply to this email, your message will be added to the discussion below: http://r.789695.n4.nabble.com/remove-loop-which-compares-row-i-to-row-i-1-tp4635327p4636372.html To unsubscribe from remove loop which compares row i to row i-1, click here. NAML -- View this message in context: http://r.789695.n4.nabble.com/remove-loop-which-compares-row-i-to-row-i-1-tp4635327p4636376.html Sent from the R help mailing list archive at Nabble.com. [[alternative HTML version deleted]]
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