Hi Yanyuan Check out: ?"==" ?"[" ?"<-" You should be able to assign the column quickly with no more than two lines of code using square brackets and assign. Or to literally use if, look at: ?"ifelse"
Happy Christmas Chris Chris Campbell Tel. +44 (0) 1249 705 450 | Mobile. +44 (0) 7929 628349 mailto:ccampb...@mango-solutions.com | http://www.mango-solutions.com Mango Solutions 2 Methuen Park Chippenham Wiltshire SN14 OGB UK -----Original Message----- From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On Behalf Of Yanyuan Zhu Sent: 20 December 2012 15:48 To: r-help@r-project.org Subject: [R] an entry level (stupid) question Hello all, i'm a newbie to R and now I get stuck by the question, would anybody help me please? Suppose, I got the following > test <- data.frame(test1=c(c(0.00, 0.005, 0.01, 0.015, 0.02))) test test1 1 0.000 2 0.005 3 0.010 4 0.015 5 0.020 Now I want another column inside test, named test2 for i=c(1:5), If test$test1[i] is 0, then the value of test$test2[i] is 1/test1[i] or else If test$test1[i] is not 0, then the value of test$test2[i] is 39 how should i programme in R to make it happen? thanks a lot! [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org 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. -- LEGAL NOTICE\ \ This message is intended for the use of ...{{dropped:18}} ______________________________________________ R-help@r-project.org 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.
