Hi R-expert, If I have this daily rainfall data, how do call a particular set of data?
Year,Month,Day,Amount 1981,1,1,0 1981,1,2,0 1981,1,3,78 1981,1,4,22 1981,1,5,2 1981,1,6,0 1981,1,7,0 1981,1,8,0 1981,1,9,0 1981,1,10,10 1981,1,11,0 1981,1,12,108 1981,1,13,328 1981,1,14,10 1981,1,15,0 1981,1,16,6 1981,1,17,0 1981,1,18,28 1981,1,19,0 1981,1,20,0 1981,1,21,0 1981,1,22,0 1981,1,23,0 1981,1,24,0 1981,1,25,32 1981,1,26,0 1981,1,27,2 1981,1,28,0 1981,1,29,2 1981,1,30,0 1981,1,31,0 1981,2,1,0 1981,2,2,118 1981,2,3,0 1981,2,4,0 1981,2,5,0 1981,2,6,12 1981,2,7,0 1981,2,8,0 1981,2,9,46 1981,2,10,4 1981,2,11,0 1981,2,12,0 1981,2,13,0 1981,2,14,0 1981,2,15,0 1981,2,16,0 1981,2,17,0 1981,2,18,0 1981,2,19,0 1981,2,20,0 1981,2,21,4 1981,2,22,16 1981,2,23,0 1981,2,24,0 1981,2,25,2 1981,2,26,0 1981,2,27,0 1981,2,28,0 1981,3,1,0 1981,3,2,0 1981,3,3,0 1981,3,4,0 1981,3,5,0 1981,3,6,0 1981,3,7,0 1981,3,8,0 1981,3,9,106 1981,3,10,10 1981,3,11,0 1981,3,12,0 1981,3,13,0 1981,3,14,0 1981,3,15,32 ... For example, if I would like to extract january and february data, and use 1/1/1901 as the origin. How do I use the dates function in R ? I did try to lookup in the manual, but not sure how to apply it? This is my code in S-plus. define.date1<-function(dt1,mt1,mt2,nn,da) { mt2<-mt2+1 start<-julian(mt1, 1, nn, origin=c(month=1, day=1, year=1971))+1 end<-julian(mt2, 1, nn, origin=c(month=1, day=1, year=1971))+da a<-dt1[start:end,] am<-as.matrix(a[,5]) } Thank you so much for your kind attention and help. ____________________________________________________________________________________ Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ ______________________________________________ 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.