diff() does not work on data.frames so you need to give it a column from the data.frame, as a vector. diff(data.frame(P=c(1,2,3,5,7,11,13,17))$P) [1] 1 1 2 2 4 2 4
You get different errors for multi- and single-column data.frames > diff(data.frame(P=c(1,2,3,5,7,11,13,17), F=c(1,1,2,3,5,8,13,21))) Error in r[i1] - r[-length(r):-(length(r) - lag + 1L)] : non-numeric argument to binary operator > diff(data.frame(P=c(1,2,3,5,7,11,13,17))) data frame with 0 columns and 8 rows Bill Dunlap TIBCO Software wdunlap tibco.com On Mon, Feb 6, 2017 at 2:21 PM, george brida <george.br...@gmail.com> wrote: > Dear R users, > > I have a txt file entitled coc composed by one column of numeric values > without header and having 50 rows. This file is under the following path: > > C:\\Users\\intel\\Documents\\TR > > I have written the following lines: > > xcx=read.table("C:\\Users\\intel\\Documents\\TR\\coc.txt",header=F) > xc=log(xcx) > > I have obtained the series xc but when I wrote > x=diff(xc) > > I obtained the following message: > > data frame with 0 columns and 50 rows > > I don't know where is the problem. Can you help me please > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. ______________________________________________ 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.