Rotation

Rotates a set of points.

rotation(x, y, rot = 90, xrot = mean(x), yrot = mean(y), rad = FALSE)

Arguments

x, y	x and y coordinates of points.
rot	angle of the rotation expressed in degree.
xrot	optional, x coordinate for the center of rotation.
yrot	optional, y coordinate for the center of rotation.
rad	logical. Should radian be used rather than degrees?

Details

Returns the coordinates of the points after rotation. If the coordinates of the rotation center are not specified, then the rotation center is the centroid of the points to be rotated.

Examples

plot0(c(0,10),c(0,10))
y <- c(6,6,9)
x <- c(2,5,3.5)
polygon(x, y, lwd=2)
myrot <- rotation(x, y, rot=90)
polygon(myrot$x, myrot$y, lwd=2, border=4)
myrot2 <- rotation(x, y, rot=-40, 0, 0)
polygon(myrot2$x,myrot2$y, lwd=2, border=3)