Refugees are welcome. Just register at the desk over there. :) Thanks, I have been drawing a complete blank without attacking it by brute force and advanced stupidity.
John Kane Kingston ON Canada > -----Original Message----- > From: [email protected] > Sent: Tue, 15 Sep 2015 20:59:59 +0000 > To: [email protected] > Subject: Re: [R] a question about data manipulation in R > > Given your "input: data frame, with variables "V1" and "V2", here's a > solution. This might not be the most "R-like" solution, since I'm still > more of a Python refugee than a native R coder. > > -John > > > # analyze input, using run-length encoding > runs_table = rle(input$V1) > number_of_runs = length(runs_table$values) # number of columns in answer > matrix > lengths_of_runs = runs_table$lengths > max_run = max(lengths_of_runs) # number of rows in answer > matrix > > # set up answer matrix, with all NA values > answer = matrix(rep(NA, number_of_runs * max_run), > nrow=max_run, ncol=number_of_runs) > > # find the locations in the input$V1 column where a new value begins > indexes = c(0, cumsum(lengths_of_runs)) + 1 > > # column-by-column: copy values from input$V2 to the answer matrix, > overwriting NA values > for (col in 1:number_of_runs) { > answer[1:lengths_of_runs[col], col] = input[ > (indexes[col]):(indexes[col+1]-1) , 2] > } > > ______________________________________________ > [email protected] 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. ____________________________________________________________ Share photos & screenshots in seconds... TRY FREE IM TOOLPACK at http://www.imtoolpack.com/default.aspx?rc=if1 Works in all emails, instant messengers, blogs, forums and social networks. ______________________________________________ [email protected] 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.
