Carsten Steinhoff <carsten.steinhoff <at> stud.uni-goettingen.de> writes:
: : Hello, : : just another problem in R, maybe it's simple to solve for you. I didn't find : a solution up to now, but I'm convinced that I'm not the only one who : has/had a similar problem. Maybe there's a ready-made function in R? : : The prob: : : I've imported a CSV-file into R with 1000 dates of an observed event : (there's only information of the date. When there happend no event the date : is not recorded, when there have been two events it's recordet twice). Now I : want to COUNT the frequency of events in every month or year. : : The CSV-data is structured as: : : date : 25.02.2003 : 29.07.1997 : ... : : My desired output would be a matrix with n rows for the years and m columns : for the month. : : How could a solution look like ? If the format is no matrix it doesn't : matter. Importend is the extraction of frequency from my data. Assuming that dd is a vector of class Date, create vectors yy and mm with the years and months as factors and then use table: yy <- as.numeric(format(dd, "%Y")) yy <- factor(yy, levels = seq(min(yy), max(yy))) mm <- factor(as.numeric(format(dd, "%m")), levels = 1:12) table(yy,mm) ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
