This function computes angle swept by a ray in anti-clockwise direction.
The ray starts at the half-line pointing towards the positive x direction,
and passes through the origin and a point defined by the user.
Usage
anglecheck(x, radians = TRUE)
Arguments
x
a vector of length 2 giving the xy-coordinates of the point defined by the user
radians
if FALSE, returns angle in degrees instead of radians
References
Khang TF, Soo OYM, Tan WB, Lim LHS. (2016). Monogenean anchor morphometry: systematic value, phylogenetic signal, and evolution. PeerJ 4:e1668.