m<-cbind(m,0) m[m[,3]>m[,4],5]<-1 colnames(m)[5]<-"censoring"
raymond chiruka wrote: > > 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 > > -- View this message in context: http://www.nabble.com/adding-a-column-to-a-matrix-tf3650601.html#a10197380 Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@stat.math.ethz.ch 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.