dat1<- read.table(text=" Product Price Year_Month PE A 100 201012 -2 A 98 201101 -3 A 97 201102 -2.5 B 110 201101 -1 B 100 201102 -2 B 90 201103 -4 ",sep="",header=TRUE,stringsAsFactors=FALSE) dat1[as.logical(with(dat1,ave(Year_Month,Product,FUN=function(x) x==max(x)))),] # Product Price Year_Month PE #3 A 97 201102 -2.5 #6 B 90 201103 -4.0 A.K.
----- Original Message ----- From: Tammy Ma <metal_lical...@live.com> To: "r-help@r-project.org" <r-help@r-project.org> Cc: Sent: Friday, March 15, 2013 5:56 AM Subject: [R] How to list the all products' information of the latest month? Hi, I have data frame like this: Product Price Year_Month PE A 100 201012 -2 A 98 201101 -3 A 97 201102 -2.5 B 110 201101 -1 B 100 201102 -2 B 90 201103 -4 How can I achieve the following result using R: Product Price Year_Month PE A 97 201102 -2.5 B 90 201103 -4 in other words, list the all products' information of the latest month? Thanks for your help. Kind regards, Lingyi [[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.
