> -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-boun...@r- > project.org] On Behalf Of madr > Sent: Tuesday, December 07, 2010 3:02 PM > To: r-help@r-project.org > Subject: [R] longer object length is not a multiple of shorter object > length > > > In datamatrix[, "y"] == datamatrix[, "y"][-1] : > longer object length is not a multiple of shorter object length > > out = c(FALSE,datamatrix[,'y'] == datamatrix[,'y'][-1]) > > and I do not know why I get that error, the resulting out matrix is > somehow > one row larger than datamatrix... > all I try to do is filter matrix by dropping rows where [,'y'][-1] == > [,'y'][+1]
If I understand what you want correctly, something like this may give you what you want # create data fraome to work with x <- 1:10 y <- c(2, 2, 4, 3, 5, 5, 4, 1, 2, 5) df <- data.frame(x,y) # out contains rows to drop out out <- which(c(FALSE, df[-1,'y'] == df[-nrow(df), 'y'])) df[-out,] # keep contains rows to keep keep <- which(c(TRUE, df[-1,'y'] != df[-nrow(df), 'y'])) df[keep,] Hope this is helpful, Dan Daniel J. Nordlund Washington State Department of Social and Health Services Planning, Performance, and Accountability Research and Data Analysis Division Olympia, WA 98504-5204 ______________________________________________ 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.
