rotmat2D {GEOmap} | R Documentation |
set a rotation matrix
rotmat2D(alph)
alph |
angle in radians |
matrix for rotation in 2 dimensions
Jonathan M. Lees<jonathan.lees@unc.edu>
######## make an ellipse theta=seq(0,360,by=5)*pi/180 r1 = 0.4 r2 = 0.2 m=matrix(rep(0,2*length(theta)),ncol=2) m[,1]=r1*cos(theta) m[,2]=r2*sin(theta) ## make a dummy plot and draw ellipse plot(c(0, 1), c(0, 1), main = "this is a test", sub = "sutitle", xlab = "this is x", ylab = "this is y") lines(m[,1]+.5, m[,2]+.5) ## get rotation matrix R = rotmat2D(32) ######### apply rotation nm=m ### plot lines(nm[,1]+.5, nm[,2]+.5, col='red')