HI, Sorry, there was a mistake, which I noticed after seeing David's post. dat1<-read.table(text=" ID V1 V2 V3 V4 1 6 5 3 2 2 3 2 2 1 3 6 5 3 2 4 12 15 3 2 5 6 8 3 2 6 3 2 4 1 7 6 5 3 3 8 12 15 3 1 9 6 5 3 3 10 3 2 7 5 11 6 5 8 2 12 12 19 3 2 13 6 5 3 2 14 3 4 2 1 15 6 5 6 2 16 12 15 5 2 17 6 5 5 2 18 3 2 8 1 19 6 5 3 9 20 12 15 3 10 21 6 5 3 2 22 3 2 2 11 23 6 5 3 4 24 12 15 9 2 25 6 5 3 2 26 3 2 2 1 27 6 5 3 2 28 12 15 3 2 29 6 8 3 2 30 3 2 4 1 31 6 5 3 3 32 12 15 3 1 33 6 5 3 3 34 3 2 7 5 35 6 5 8 2 36 12 19 3 2 37 6 5 3 2 38 3 4 2 1 ",sep="",header=TRUE,stringsAsFactors=FALSE) res<-aggregate(.~(1:nrow(dat1)-1)%/%12,data=dat1[,-1],mean) names(res)[1]<-"group" A.K.
----- Original Message ----- From: Simonas Kecorius <simolas2...@gmail.com> To: r-help@r-project.org Cc: Sent: Saturday, January 5, 2013 8:33 AM Subject: [R] Need help on dataframe Dear R users, I came up to a problem by taking means (or other summary statistics) of a big dataframe. Suppose we do have a dataframe: ID V1 V2 V3 V4 ........................ V71 1 6 5 3 2 ........................ 3 2 3 2 2 1 ........................ 1 3 6 5 3 2 ........................ 3 4 12 15 3 2 ........................ 100 ........................................................ ........................................................ 288 10 20 30 30 .......................... 499 I need to find out the way, how to calculate a mean of every 12 lines to get: V1 V2 V3 V4 ........................... V71 mean from 1 to 7 same as V1 same as V1 mean from 8 to 14 same as V1 same as V1 etc. I can do it column by column using: y.ts <- ts(y$V1, frequency=12) aggregate(y.ts, FUN=mean) Bu this is a hardcore... Can anyone suggest a better way to compute all the dataframe at once and get a result as matrix? Thank you in advance! -- Simonas Kecorius ** [[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.
