Hi, Try this: dat1<- read.table(text=" DEPTH SALINITY DEPTH SALINITY 18 87 39.06 94 39.06 19 173 39.05 141 NA 20 260 39.00 188 39.07 21 312 38.97 207 39.03 22 1 39.36 1 39.35 23 10 39.36 10 39.33 24 20 39.36 20 39.33 25 30 39.35 30 39.33 ",sep="",header=TRUE)
library(matrixStats) res<-dat1[rowDiffs(as.matrix(dat1[,c(1,3)]))==0,] res # DEPTH SALINITY DEPTH.1 SALINITY.1 #22 1 39.36 1 39.35 #23 10 39.36 10 39.33 #24 20 39.36 20 39.33 #25 30 39.35 30 39.33 #or dat1[apply(dat1,1,function(x) x[1]-x[3]==0),] # DEPTH SALINITY DEPTH.1 SALINITY.1 #22 1 39.36 1 39.35 #23 10 39.36 10 39.33 #24 20 39.36 20 39.33 #25 30 39.35 30 39.33 A.K. ----- Original Message ----- From: Ellie Papazisi <elliepapaz...@gmail.com> To: r-help@r-project.org Cc: Sent: Tuesday, June 11, 2013 11:45 AM Subject: [R] extract common rows from a dataframe Hello, I'm trying to extract the common rows from a data frame, which is something like this : * DEPTH SALINITY DEPTH SALINITY* *18 87 39.06 94 39.06* *19 173 39.05 141 NA* *20 260 39.00 188 39.07* *21 312 38.97 207 39.03* *22 1 39.36 1 39.35* *23 10 39.36 10 39.33* *24 20 39.36 20 39.33* *25 30 39.35 30 39.33* * * i want to extract the rows with the same depth. i cannot do something like *data.frame[22:25,]* because i have lots of rows any help? thank you [[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.
