Of course it _should_ be: ifelse(x[-length(x)] < x[-1], ...,...)
Sorry... -- Bert On Tue, Jul 3, 2012 at 1:00 PM, Bert Gunter <bgun...@gene.com> wrote: > Vectorize vectorize vectorize! > > if(x[-length(x)] < x[-1]) {...} > > (where x is the whole vector of entries) > > Bill Dunlap has posted some elegant code within the last month or 2 aimed > at this sort of thing, so search on his posts in the archive. > > -- Bert > > On Tue, Jul 3, 2012 at 12:10 PM, jcrosbie <ja...@crosb.ie> wrote: > >> >> I would like to remove a loop to speed up my code. >> >> I want to remove a loop which references the last row. >> >> In general I want to a remove a loop which looks something like this: >> for 2 to number of rows in a matrix do{ >> if indextrow-1 is < currentIndexRow then do something. >> } >> >> >> My R code: >> >> for (i in 2:length(tUnitsort$Hour)){ >> ifelse(tUnitsort[i,4]>=tUnitsort[i-1,4],(tempMC >> =tUnitsort[i,7]),tempMC ) #col. 4 = BlockNumber; note tests to see if the >> offers have change to the next set of blocks. >> ifelse(tUnitsort[i,4]>=tUnitsort[i-1,4],(tempAC >> =tUnitsort[i,7]-(tUnitsort[i,8]-tUnitsort[i,9])),tempAC ) >> tUnitsort$MC[i] <- tempMC >> tUnitsort$AC[i] <- tempAC >> tUnitsort$PercentofMC[i] <- tUnitsort$Size[i]/tempMC >> tUnitsort$PercentofAC[i] <- tUnitsort$AvailableMW[i]/tempAC >> } >> >> -- >> View this message in context: >> http://r.789695.n4.nabble.com/remove-loop-which-compares-row-i-to-row-i-1-tp4635327.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. >> > > > > -- > > Bert Gunter > Genentech Nonclinical Biostatistics > > Internal Contact Info: > Phone: 467-7374 > Website: > > http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm > > > -- Bert Gunter Genentech Nonclinical Biostatistics Internal Contact Info: Phone: 467-7374 Website: http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm [[alternative HTML version deleted]] ______________________________________________ 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.