I haven't been following your discussion, but based on your method, the following should also work and would be the one-line equivalent:
m$act.surv.time<-pmin(m[,"censoringTime"],m[,"survivalTime"]) In other words, you can add a column by just assigning a value to a new column name. You can also use the following syntax: m$act.surv.time<-pmin(m$"censoringTime",m$"survivalTime") I just thought you might want to see different version of accomplishing the same thing. Roger. -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of raymond chiruka Sent: Tuesday, May 08, 2007 12:36 PM To: Schmitt, Corinna; r Subject: Re: [R] creating a new column thanks for the help But l ened up using act.surv.time<-pmin(m[,"censoringTime"],m[,"survivalTime"]) m<-cbind(m,act.surv.time) which seems to work thanks "Schmitt, Corinna" <[EMAIL PROTECTED]> wrote: Hallo, I just tried, if my solution might be possible for you. Here is the result: > s=2 > while(s!=0){ n=20 + m<-matrix(nrow=n,ncol=4) + colnames(m)=c("treatmentgrp","strata","censoringTime","survivalTime") + for(i in 1:20) m[i,]<-c(sample(c(1,2),1,replace=TRUE),sample(c(1,2),1,replace=TRUE),rexp(1,.007),rexp(1,.002)) + m<-cbind(m,0) + m[m[,3]>m[,4],5]<-1 + colnames(m)[5]<-"censoring" + print(m) + s=s-1 + } #bilding a data frame from m x=data.frame(m) # adding a column, where nrow(x) = number of row in x and in the # new coulmn should stand the entries 1...20. x=data.frame(x,"actual surv time"=c(1:nrow(x))) > x treatmentgrp strata censoringTime survivalTime censoring actual.surv.time 1 1 2 377.486125 1070.66287 0 1 2 1 2 242.468604 1061.30474 0 2 3 1 2 40.904656 51.88263 0 3 4 2 2 44.025595 590.15317 0 4 5 1 1 253.093279 247.32141 1 5 6 2 2 50.486272 257.25016 0 6 7 1 1 337.591250 554.05931 0 7 8 2 2 74.905075 873.14563 0 8 9 1 2 57.196581 765.43142 0 9 10 1 2 370.147307 1646.65368 0 10 11 1 2 152.738532 480.12355 0 11 12 2 2 15.313303 139.19791 0 12 13 1 2 17.205624 641.15764 0 13 14 2 1 81.753924 107.02202 0 14 15 1 2 60.774221 665.27500 0 15 16 2 1 8.712562 142.90775 0 16 17 1 1 54.542722 1904.88060 0 17 18 2 2 85.626140 214.66811 0 18 19 2 1 31.257923 739.96591 0 19 20 1 1 85.910141 306.14860 0 20 See it works! For more information of data frames, see ?data.frame Here are some additional examples. > x[2,6] # Extraction of special entries: x[2,6]= 2 -> row 2, column 6 [1] 2 > x[2,6]=100 # Changing entires: x[2,6]=100 > x treatmentgrp strata censoringTime survivalTime censoring actual.surv.time 1 1 2 377.486125 1070.66287 0 1 2 1 2 242.468604 1061.30474 0 100 3 1 2 40.904656 51.88263 0 3 4 2 2 44.025595 590.15317 0 4 5 1 1 253.093279 247.32141 1 5 6 2 2 50.486272 257.25016 0 6 7 1 1 337.591250 554.05931 0 7 8 2 2 74.905075 873.14563 0 8 9 1 2 57.196581 765.43142 0 9 10 1 2 370.147307 1646.65368 0 10 11 1 2 152.738532 480.12355 0 11 12 2 2 15.313303 139.19791 0 12 13 1 2 17.205624 641.15764 0 13 14 2 1 81.753924 107.02202 0 14 15 1 2 60.774221 665.27500 0 15 16 2 1 8.712562 142.90775 0 16 17 1 1 54.542722 1904.88060 0 17 18 2 2 85.626140 214.66811 0 18 19 2 1 31.257923 739.96591 0 19 20 1 1 85.910141 306.14860 0 20 > t=x > row2=t[-2,] # deleting a row > row2 treatmentgrp strata censoringTime survivalTime censoring actual.surv.time 1 1 2 377.486125 1070.66287 0 1 3 1 2 40.904656 51.88263 0 3 4 2 2 44.025595 590.15317 0 4 5 1 1 253.093279 247.32141 1 5 6 2 2 50.486272 257.25016 0 6 7 1 1 337.591250 554.05931 0 7 8 2 2 74.905075 873.14563 0 8 9 1 2 57.196581 765.43142 0 9 10 1 2 370.147307 1646.65368 0 10 11 1 2 152.738532 480.12355 0 11 12 2 2 15.313303 139.19791 0 12 13 1 2 17.205624 641.15764 0 13 14 2 1 81.753924 107.02202 0 14 15 1 2 60.774221 665.27500 0 15 16 2 1 8.712562 142.90775 0 16 17 1 1 54.542722 1904.88060 0 17 18 2 2 85.626140 214.66811 0 18 19 2 1 31.257923 739.96591 0 19 20 1 1 85.910141 306.14860 0 20 > column3=t[,-3] # deleting a column > column3 treatmentgrp strata survivalTime censoring actual.surv.time 1 1 2 1070.66287 0 1 2 1 2 1061.30474 0 100 3 1 2 51.88263 0 3 4 2 2 590.15317 0 4 5 1 1 247.32141 1 5 6 2 2 257.25016 0 6 7 1 1 554.05931 0 7 8 2 2 873.14563 0 8 9 1 2 765.43142 0 9 10 1 2 1646.65368 0 10 11 1 2 480.12355 0 11 12 2 2 139.19791 0 12 13 1 2 641.15764 0 13 14 2 1 107.02202 0 14 15 1 2 665.27500 0 15 16 2 1 142.90775 0 16 17 1 1 1904.88060 0 17 18 2 2 214.66811 0 18 19 2 1 739.96591 0 19 20 1 1 306.14860 0 20 Happy working, Corinna -----Ursprüngliche Nachricht----- Von: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Im Auftrag von Schmitt, Corinna Gesendet: Dienstag, 8. Mai 2007 10:06 An: raymond chiruka; r Betreff: Re: [R] creating a new column Hallo, I just now a solution for da data frame. I'm not sure if this is what you want. Just try if it helps. Here an example of my code where I added a column: df <- rbind( c("fred","mary",4),c("fred","mary",7), c("fred","mary",9),c("barney","liz",3), c("barney","liz",5)) df <- data.frame(df) colnames(df) <- c("father","mother","child.age") # adding column df <- data.frame(df,"weddingdate"=c("Dec 12th, 1980","Dec 12th, 1980", "Dec 12th, 1980","Apr 9th, 2003", "Apr 9th, 2003")) df The R-Gui Result: father mother child.age weddingdate 1 fred mary 4 Dec 12th, 1980 2 fred mary 7 Dec 12th, 1980 3 fred mary 9 Dec 12th, 1980 4 barney liz 3 Apr 9th, 2003 5 barney liz 5 Apr 9th, 2003 Caution: the number of entries in adding column must correspond to the number of rows in your existing data frame df (here 5) Try this soultion, Corinna -----Ursprüngliche Nachricht----- Von: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Im Auftrag von raymond chiruka Gesendet: Montag, 7. Mai 2007 16:28 An: r Betreff: [R] creating a new column hie l would like to create a 6th column "actual surv time" from the following data the condition being if censoringTime>survivaltime then actual survtime =survival time else actual survtime =censoring time the code l used to create the data is s=2 while(s!=0){ n=20 m<-matrix(nrow=n,ncol=4) colnames(m)=c("treatmentgrp","strata","censoringTime","survivalTime") for(i in 1:20) m[i,]<-c(sample(c(1,2),1,replace=TRUE),sample(c(1,2),1,replace=TRUE),rexp(1,.007),rexp(1,.002)) m<-cbind(m,0) m[m[,3]>m[,4],5]<-1 colnames(m)[5]<-"censoring" print(m) s=s-1 treatmentgrp strata censoringTime survivalTime censoring [1,] 1 1 1.012159 1137.80922 0 [2,] 2 2 32.971439 247.21786 0 [3,] 2 1 85.758253 797.04949 0 [4,] 1 1 16.999171 78.92309 0 [5,] 2 1 272.909896 298.21483 0 [6,] 1 2 138.230629 935.96765 0 [7,] 2 2 91.529859 141.08405 0 l keep getting an error message when i try to create the 6th column --------------------------------- [[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. ______________________________________________ [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. --------------------------------- [[alternative HTML version deleted]] ********************************************************************** * This message is for the named person's use only. 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