Rotation {spdep} | R Documentation |
Rotate a set of XY coordinates by an angle (in radians)
Rotation(xy, angle)
xy |
A 2-columns matrix or data frame containing a set of X and Y coordinates. |
angle |
Numeric. A scalar giving the angle at which the points should be rotated. The angle is in radians. |
A 2-columns matrix of the same size as xy
giving the rotated coordinates.
F. Guillaume Blanchet
set.seed(1) ### Create a set of coordinates coords<-cbind(runif(20),runif(20)) ### Create a series of angles rad<-seq(0,pi,l=20) opar <- par(mfrow=c(5,4)) for(i in rad){ coords.rot<-Rotation(coords,i) plot(coords.rot) } par(opar) ### Rotate the coordinates by an angle of 90 degrees coords.90<-Rotation(coords,90*pi/180) coords.90 plot(coords,xlim=range(rbind(coords.90,coords)[,1]),ylim=range(rbind(coords.90,coords)[,2]),asp=1) points(coords.90,pch=19)