Dear all, I'm completely new to R and at first I must say that it is a great program!
But I have a problem with the function isoMDS from the MASS package. I have this code which I load with source() from a file: x <- c(163.59514923926784, 150.01448475257115, ...... {here are some more values}) x.sort <- sort(x) x.dist <- dist(x.sort) library(MASS) x.mds <- isoMDS(x.dist) plot(x.mds$points, type="n") text(x.mds$points, labels=as.character("x")) The problem is in the line where the isoMDS function is applied: I got the error: Fehler in isoMDS(x.dist) : zero or negative distance between objects 9 and 10 When I look at values 8 and 9 of x.dist, I see that they have the same values (I'm not wrong, it's values of 8 and 9 and not 9 and 10): x.dist[8:9] [1] 39.8214 39.8214 So, just to give'm a try, I changed the value of x.dist[8]: x.dist[8] <- c(39.7) Now, there are defintitely different values in this part of x.dist: x.dist[7:10] [1] 39.69898 39.70000 39.82140 39.98892 But when I start isoMDS again, I got again the error: x.mds <- isoMDS(x.dist) Fehler in isoMDS(x.dist) : zero or negative distance between objects 9 and 10 So, where's my error? Thank you! Best, Tom -- ---------------------------- http://www.thomas-zastrow.de German Forum - DTP under Linux: http://www.opendtp.de ______________________________________________ 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.