Hi Uwe, It works. Why does the following argument generate different results? with(data, arrows(x[-length(x)], y[-length(x)], x[-1], y[-1])) #correct,multiple joins with(data, arrows(x[1], y[1], x[length(x)], y[length(x)])) #wrong,seems to be only one join From the ?arrows, the second argument should work. What is the problem? Thanks a lot. #codes: x<-c(1:6);y<-c(1:6);time<-c(6:1);data<-cbind(x,y,time);data data<-data.frame(data[order(data[,"time"]),]) with(data, plot(x,y)) with(data, arrows(x[-length(x)], y[-length(x)], x[-1], y[-1]))
with(data, plot(x,y)) with(data, arrows(x[1], y[1], x[length(x)], y[length(x)])) 2009/11/4 Uwe Ligges <lig...@statistik.tu-dortmund.de> > > > zhijie zhang wrote: > >> Hi, >> I have a data set with three variables,X Y and Time. X and Y are the >> coordinates of points, i want to join these points according to the Time >> sequence using arrows? >> Demo Example data: >> >>> x<-c(1:6) >>> y<-c(1:6) >>> time<-c(6:1) >>> data<-cbind(x,y,time) >>> data >>> >> x y time >> [1,] 1 1 6 >> [2,] 2 2 5 >> [3,] 3 3 4 >> [4,] 4 4 3 >> [5,] 5 5 2 >> [6,] 6 6 1 >> I hope to join the six points with points' time=1 as starting point and >> points' time=6 as endpoint. So the sequence is time=1,2,3,4,5,6 and join >> the >> corresponding points with arrows. >> Any ideas on it? >> > > > data <- data.frame(data[order(data[,"time"]),]) > with(data, plot(y ~ x)) > with(data, arrows(x[-length(x)], y[-length(x)], x[-1], y[-1])) > > > Uwe Ligges > > > [[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<http://www.r-project.org/posting-guide.html> >> and provide commented, minimal, self-contained, reproducible code. >> > [[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.
