just try: cbind(m, m[, "censti"] > m[, "survtime"])
I hope it helps. Best, Dimitris ---- Dimitris Rizopoulos Ph.D. Student Biostatistical Centre School of Public Health Catholic University of Leuven Address: Kapucijnenvoer 35, Leuven, Belgium Tel: +32/(0)16/336899 Fax: +32/(0)16/337015 Web: http://med.kuleuven.be/biostat/ http://www.student.kuleuven.be/~m0390867/dimitris.htm ----- Original Message ----- From: "raymond chiruka" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Thursday, April 26, 2007 11:31 AM Subject: [R] adding a column to a matrix >i would like to add a variable to an existing matrix by manipulating >2 previous variables eg for the data > m > treat strata censti survTime > [1,] 1 2 284.684074 690.4961005 > [2,] 1 1 172.764515 32.3990335 > [3,] 1 1 2393.195400 24.6145279 > [4,] 2 1 30.364771 8.0272267 > [5,] 1 1 523.182282 554.7659501 > > l would want to add a new column censoring by comparing ( if censti > > survtime then censoring=1) how do l go about it > thanks > > the code l used to generate the data is > n=100 > > m=matrix(nrow=n,ncol=4) > > colnames(m)=c("treat", "strata", "censti", "survTime") > > for(i in 1:100) > m[i,]=c(sample(c(1,2),1,replace=TRUE),sample(c(1,2),1,replace=TRUE),rexp(1,.002),rexp(1,.005)) > > m > > l know its ugly but it seems to work > any suggestions l still new at this > thanks > > > > > --------------------------------- > > > [[alternative HTML version deleted]] > > ______________________________________________ > [email protected] 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. > Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm ______________________________________________ [email protected] 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.
