Hello, I created a data.frame which contains two columns: df$P (Power) et df$DateTime (time). I'd like to add a new column df$diffP (difference of Power between T and T-2).
I made a loop : for (i in 3:length(df$DateTime)){ df$diffP[i] = df$P[i] - df$P[i-2] } execution time result is unaceptable: 24s !! Is there any way to reduce complexity about O(n) ? for example 2 or 3s (10s maxi) Does anybody find better than ~24s ? thanks for your help -- View this message in context: http://r.789695.n4.nabble.com/data-frame-temporal-complexity-tp4269585p4269585.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.