Hi all, I am trying to summarize big data set by selecting a row conditionally. and tried to do it in a loop
Here is the sample of my data and my attempt dat<-read.table(text=" ID,x1,x2,y 1,a,b,15 1,x,z,21 1,x,b,16 1,x,k,25 2,d,z,31 2,x,z,28 2,g,t,41 3,h,e,32 3,x,z,38 3,x,g,45 ",sep=",",header=TRUE) For each unique ID, I want to select a data when x1= "x" and x2="z" Here is the selected data (newdat) ID,x1,x2,y 1,x,z,21 2,x,z,28 3,x,z,38 Then I want summarize Y values and out put as follows Summerize summary(newdat[i]) ###################################################### ID Min. 1st Qu. Median Mean 3rd Qu. Max. 1 2 3 . . . 28 #################################################### Here is my attempt but did not work, trt=c(1:28) for(i in 1:length (trt)) { day[i]= newdat[which(newdat$ID== trt[i] & newdat$x1 =="x" & newdat$x2 =="z"),] NR[i]=dim(day[i])[1] print(paste("Number of Records :", NR[i])) sm[i]=summary(day[i]) } Thank you in advance ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.