Hi, Please check: ?FAQ 7.31 http://cran.r-project.org/doc/FAQ/R-FAQ.html#Why-doesn_0027t-R-think-these-numbers-are-equal_003f
intervalloweredge[3]-3.845 #[1] -4.440892e-16 which(as.character(intervalloweredge)=="3.845") #[1] 3 which(as.character(intervalloweredge)=="3.86") #[1] 4 #or which(round(intervalloweredge,3)==3.845) #[1] 3 A.K. Greetings I am trying to create an interval list as follows: interval <- 0.015 intervalloweredge <- 3.815+interval*seq(0,5, by=1) intervalupperedge <- intervalloweredge + interval Here is the output when I type intervalloweredge: [1] 3.815 3.830 3.845 3.860 3.875 3.890 All seems well... but then R won't find intervalloweredge[3]: which(intervalloweredge==3.815) [1] 1 > which(intervalloweredge==3.83) [1] 2 > which(intervalloweredge==3.845) integer(0) > which(intervalloweredge==3.86) [1] 4 > which(intervalloweredge==3.875) [1] 5 > which(intervalloweredge==3.89) [1] 6 Likewise Here is the output when I type intervalupperedge: [1] 3.830 3.845 3.860 3.875 3.890 3.905 but then R won't find intervalupperedge[6]: > which(intervalupperedge==3.83) [1] 1 > which(intervalupperedge==3.845) [1] 2 > which(intervalupperedge==3.86) [1] 3 > which(intervalupperedge==3.875) [1] 4 > which(intervalupperedge==3.89) [1] 5 > which(intervalupperedge==3.905) integer(0) Instead, I have to define the intervals by hand, like this: alt <- 0.015 altlower <- c(3.815, 3.83, 3.845, 3.86, 3.875, 3.89) altupper <- c(3.83, 3.845, 3.86, 3.875, 3.89, 3.905) Then R will find each entry in both arrays fine. What's going on? Why can't I use the "interval" variables in the way that I've set them up? Also, I received a message saying that I needed to subscribe, before my post would be accepted. I tried clicking on the Subscribe button and was taken to a page where I was asked to check my email for a subscription confirm. But I never received the email. Did my post get accepted? How do I know? Because I have posts in other threads from months back that have yet to be accepted. ______________________________________________ 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.
