Hi, May be this helps. date1<-seq.Date(as.Date("01/01/2000",format="%d/%m/%Y"),as.Date("31/12/2010",format="%d/%m/%Y"),by="day") set.seed(24) value<- rnorm(4018,25) dat1<- data.frame(date1,value) dat2<- do.call(rbind,split(dat1,as.numeric(gsub(".*\\-(.*)\\-.*","\\1",dat1$date1))))
library(zoo) z1<- as.zoo(dat2) tail(z1,50) date1 value 3969 2009-12-13 24.82354 3970 2009-12-14 25.01100 3971 2009-12-15 24.22370 3972 2009-12-16 26.20387 3973 2009-12-17 23.94170 3974 2009-12-18 24.39037 3975 2009-12-19 25.01231 3976 2009-12-20 25.25939 3977 2009-12-21 23.57236 3978 2009-12-22 26.42321 3979 2009-12-23 24.72704 3980 2009-12-24 24.60001 3981 2009-12-25 24.23091 3982 2009-12-26 23.63178 3983 2009-12-27 25.02472 3984 2009-12-28 25.58247 3985 2009-12-29 24.79180 3986 2009-12-30 24.93262 3987 2009-12-31 23.96313 3988 2010-12-01 25.83565 3989 2010-12-02 24.45985 3990 2010-12-03 25.17499 3991 2010-12-04 24.57330 3992 2010-12-05 24.52134 3993 2010-12-06 24.71778 3994 2010-12-07 25.81350 3995 2010-12-08 25.35647 3996 2010-12-09 24.50438 3997 2010-12-10 24.12099 3998 2010-12-11 25.16103 3999 2010-12-12 24.03809 4000 2010-12-13 24.31008 4001 2010-12-14 24.09804 4002 2010-12-15 25.58613 4003 2010-12-16 25.19094 4004 2010-12-17 25.75322 4005 2010-12-18 24.30318 4006 2010-12-19 24.79664 4007 2010-12-20 23.58302 4008 2010-12-21 24.37014 4009 2010-12-22 23.28147 4010 2010-12-23 23.70687 4011 2010-12-24 26.17041 4012 2010-12-25 24.76579 4013 2010-12-26 25.49849 4014 2010-12-27 23.64199 4015 2010-12-28 23.97338 4016 2010-12-29 24.96617 4017 2010-12-30 24.07872 4018 2010-12-31 25.25245 A.K. ----- Original Message ----- From: Zilefac Elvis <zilefacel...@yahoo.com> To: "r-help@r-project.org" <r-help@r-project.org> Cc: Sent: Wednesday, May 22, 2013 11:11 PM Subject: [R] Sort data by month Hello, I have a 'zoo' object containing dates [dd/mm/yr] in the first column and values in the second column. I tried as.Date but did not succeed. Here is an example of date format 01/01/2000 01/02/2000 ... 01/12/2000 01/01/2001 01/02/2001 ... 01/12/2000 etc. I would like to sort all Jans from 2000 to 2010, all Febs from 2000 to 2010 ... all Decs from 2000 to 2010. So, basically I would like to sort by month. Thanks for your help. Atem. [[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. ______________________________________________ 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.