Dear R users, I have a huge database and I need to adjust it somewhat.
Here is a very little cut out from database: CODE NAME DATE DATA1 4813 ADVANCED TELECOM 1987 0.013 3845 ADVANCED THERAPEUTIC SYS LTD 1987 10.1 3845 ADVANCED THERAPEUTIC SYS LTD 1989 2.463 3845 ADVANCED THERAPEUTIC SYS LTD 1988 1.563 2836 ADVANCED TISSUE SCI -CL A 1987 0.847 2836 ADVANCED TISSUE SCI -CL A 1989 0.872 2836 ADVANCED TISSUE SCI -CL A 1988 0.529 What I need is: 1) Delete all cases containing -CL A (and also -OLD, -ADS, etc) at the end 2) Delete all cases that have less than 3 years of data 3) For each remaining case compute ratio DATA1(1989) / DATA1(1987) [and then ratios involving other data variables] and output this into new database consisting of CODE, NAME, RATIOs. Maybe someone can suggest an effective way to do these things? I imagine the first one would involve grep(), and 2 and 3 would involve apply family of functions, but I cannot get my mind around the actual code to perform this adjustments. I am new to R, I do write code but usually it consists of for-functions and plotting. I would much appreciate your help. Thank you in advance! -- Jonas Malmros Stockholm University Stockholm, Sweden ______________________________________________ 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.
