Hi, everyone I got some problems when trying to subscript the value of vector and list, by using calculated indices. Here is the vector I am generated lon<-rep(0,886);lat<-rep(0,691) for (i in 1:886){ lon[i]<-112+0.05*(i-1) } for (i in 691:1){ lat[i]<--44.5+0.05*(691-i) } For a given location of lon(xp) and lat(yp), I would like to calculate the position of them, and using that to get the value for the location from one list. xp<-c(112,112.05); yp<-c(-10,-10.10)
x<-rep(0,length(xp)); y<-rep(0,length(yp)) for (i in 1:length(xp)){ x[i]<-(xp[i]-112)/0.05+1 } for(j in 1:length(yp)){ y[j]<-(-10-yp[j])/0.05+1 } So here the value of x and y should indicate the position where xp and yp are in the vector lon and lat. And it appears to be the right number. But when I tried to retrieve the value of lon using the position, it returns the wrong value. Here's the result I got > x [1] 1 2 > lon[x] [1] 112 112 > lon[c(1,2)] [1] 112.00 112.05 > y [1] 1 3 > lat[y] [1] -10.00 -10.05 > lat[c(1,3)] [1] -10.0 -10.1 I have no idea why it returns the wrong value when I subscripts by x, while it works perfectly fine when I subscripts with the value of x directly. Is there any special rule of subscripts? My version of R is 2.5.1. Thanks a lot Jingru Dai ---- School of Mathematical Sciences Rm 454, Building 28 Monash University, 3800 Victoria, Australia ______________________________________________ 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.