[R] Data extraction and assembly from a data frame

Hi all, Here is my situation. I have a dataframe, the structure would be something like this, TestData-data.frame(ID=rep(1:10,each=10),TIME=rep(seq(0.1,1,0.1),10),VAR1=rnorm(100),VAR2=5*rnorm(100),VAR3=10*rnorm(100)) Basically, I want to extract the maximum value from each ID for VAR1, VAR2,

Re: [R] Data extraction and assembly from a data frame

How about aggregate(TestData[,c('VAR1','VAR2','VAR3')], by=list(id=TestData$ID), FUN=max) -- Don MacQueen Lawrence Livermore National Laboratory 7000 East Ave., L-627 Livermore, CA 94550 925-423-1062 On 6/20/14 12:42 PM, Jun Shen jun.shen...@gmail.com wrote: Hi all, Here is my

Re: [R] Data extraction and assembly from a data frame

Have you looked at the 'aggregate' function? E.g., aggregate(TestData[c(VAR1,VAR2,VAR3)], by=TestData[ID], max) Bill Dunlap TIBCO Software wdunlap tibco.com On Fri, Jun 20, 2014 at 12:42 PM, Jun Shen jun.shen...@gmail.com wrote: Hi all, Here is my situation. I have a dataframe, the

Re: [R] Data extraction and assembly from a data frame

You could try: library(plyr) res - ddply(TestData[,-2],.(ID),numcolwise(max)) colnames(res)[-1] - paste0(colnames(res)[-1],.max) A.K. On Friday, June 20, 2014 3:43 PM, Jun Shen jun.shen...@gmail.com wrote: Hi all, Here is my situation. I have a dataframe, the structure would be something

Re: [R] Data extraction and assembly from a data frame

Hi Don, Bill and A.K. Thanks for your reply. It worked! On Fri, Jun 20, 2014 at 3:56 PM, arun smartpink...@yahoo.com wrote: You could try: library(plyr) res - ddply(TestData[,-2],.(ID),numcolwise(max)) colnames(res)[-1] - paste0(colnames(res)[-1],.max) A.K. On Friday, June 20, 2014