I have a data frame, where two last columns - "month" and "year" - are character vectors. The "year" vector is made of two numbers (i.e. "97" for 1997, "07" for 2007, etc) What I want to do is to create a variable "Year" that is mode numeric and where each record is a four-figure number (1997, 2007,...) I have about 40000 rows in the dataframe, the observations are for 10 years (so there are multiple rows for each year). I tried the following, but the program runs and runs, and if I abort it all the years in "Year" are 1997:
for(i in 1:dim(database)[1]){ if(database$year[i]>90) { database$Year[i] <- as.numeric(database$year[i])+1900 } else { database$Year[i] <- as.numeric(database$year[i])+2000 } } Thanks in advance for explanations. Regards, JM -- 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.