Hello R-users, I have a very simple problem I wanted to solve. I have a large dataset as such: Lag X.Symbol Time TickType ReferenceNumber Price Size X.Symbol.1 Time.1 TickType.1 ReferenceNumber.1 1 ES 3:ESZ7.GB 08:30:00 B 74390987 151075 44 3:ESZ7.GB08:30:00 A 74390988 2 ES 3:YMZ7.EC 08:30:00 B 74390993 13686 17 3:YMZ7.EC08:30:00 A 74390994 3 YM 3:ESZ7.GB 08:30:00 B 74391135 151075 49 3:ESZ7.GB08:30:00 A 74391136 4 YM 3:YMZ7.EC 08:30:00 B 74390998 13686 17 3:YMZ7.EC08:30:00 A 74390999 5 YM 3:ESZ7.GB 08:30:00 B 74391135 151075 49 3:ESZ7.GB08:30:00 A 74391136 6 YM 3:YMZ7.EC 08:30:00 B 74391000 13686 14 3:YMZ7.EC08:30:00 A 74391001 Price.1 Size.1 LeadTime MidPoint Spread 1 151100 22 08:30:00 *151087.5* 25 2 13688 27 08:30:00 13687.0 2 3 151100 22 08:30:00 *151087.5* 25 4 13688 27 08:30:00 13687.0 2 5 151100 22 08:30:00 151087.5 25 6 13688 27 08:30:00 13687.0 2
All I wanted to do was take the Log(MidPoint[2]) - Log(MidPoint[1]) for a symbol "3:ESZ7.GB" So the first one would be log(151087.5) - log(151087.5). I wanted to do this throughout the data set and add that in another column. I would appreciate any help. Regards, Neil Gupta [[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.