Angles between vectors.

Calcul the angles of two set of vectors.

getAngle2d(x0, y0, x1, y1, rad = FALSE)

Arguments

x0	the x coordinates of the first set of vector.
y0	the y coordinates of the first set of vector.
x1	the x coordinates of the second set of vector.
y1	the y coordinates of the second set of vector.
rad	a logical. Should angles be expressed radians?

Examples

#Example:
plot0(c(-10,10),c(-10,10))
arrows(c(0,3),c(0,0),c(3,0),c(3,-3))
cool <- getAngle2d(c(0,3),c(0,0),c(3,0),c(3,-3))