data1$A[8] #[1] 1.4 data2$A[15] #[1] 1.4 data2$A[15]==data1$A[8] #[1] FALSE
You can check these links: http://r.789695.n4.nabble.com/Comparing-decimal-numbers-td3251437.html http://rwiki.sciviews.org/doku.php?id=misc:r_accuracy A.K. >The FAQ says "Other numbers have to be rounded to (typically) 53 binary digits >accuracy." >These numbers are clearly a bit less than that. Also, I've defined these numbers, they were not calculated through a multiplication or division >operation. I would hate to think that R would have trouble with such a basic operation. I must be doing something wrong. ----- Original Message ----- From: arun <smartpink...@yahoo.com> To: R help <r-help@r-project.org> Cc: Sent: Wednesday, May 29, 2013 2:33 AM Subject: Re: Problems with merge HI, Possibly R FAQ: 7.31 data1New<-data1 data1New$A<- round(data1New$A,2) data2New<- data2 data2New$A<- round(data2New$A,2) merge(data1New,data2New,by="A") # A B C #1 0.0 0.9 10.0 #2 1.1 0.6 11.1 #3 1.4 0.7 11.4 #4 3.1 0.4 13.1 #5 4.4 0.8 14.4 A.K. Hello, Lets say we have these two data frames: data1<-data.frame(c(1.23,1.363332,6.43209,4.230593,3.10294,5.09333,1.1,1.4,4.4,0),seq(0,by=0.1,length.out=10)) names(data1)<-c("A","B") data2<-data.frame(seq(0,6,by=0.1),seq(10,16,by=0.1)) names(data2)<-c("A","C") And we would like to merge only the similar values from column "A". merge(data1,data2,by="A",all=FALSE) we get: A B C 1 0.0 0.9 10.0 2 1.1 0.6 11.1 3 4.4 0.8 14.4 Unfortunately, it's missing the value of 1.4 in both data.frame columns "A". Similarly, if we instead use: merge(data1,data2,by="A",all=TRUE) the value of 1.4 is duplicated while 0, 1.1, and 4.4 is not. All of the mathematical functions work as they should on the 1.4, yet merge seems to think that the two 1.4 in the different data frames are completely different values. I must be going crazy, because I use the merge function all the time and I've never run into this problem before. Thanks. ______________________________________________ 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.
