Gyrocenroid of a triangle.
gyrocentroid(A, B, C, s = 1, model = "U")A point, the gyrocentroid of the triangle ABC.
three distinct points
positive number, the radius of the Poincaré ball if
model="M", otherwise, if model="U", this number
defines the hyperbolic curvature (the smaller, the more curved)
the hyperbolic model, either "M" (Möbius model, i.e.
Poincaré model) or "U" (Ungar model, i.e. hyperboloid model)