Re: [R] adding a column to a matrix 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.