Kernel::ComputePowerProduct_2 Concept Reference

Definition

Refines:

AdaptableFunctor (with two arguments)

See also

CGAL::Weighted_point_2<Kernel>

ComputePowerProduct_3

Operations
A model of this concept must provide:
Kernel::FT	operator() (const Kernel::Weighted_point_2 &pw, const Kernel::Weighted_point_2 &qw) const
	returns the power product of pw and qw. More...

Member Function Documentation

operator()()

Kernel::FT Kernel::ComputePowerProduct_2::operator()	(	const Kernel::Weighted_point_2 &	pw,
		const Kernel::Weighted_point_2 &	qw
	)		const

returns the power product of pw and qw.

Let \( {p}^{(w)} = (p,w_p), p\in\mathbb{R}^2, w_p\in\mathbb{R}\) and \( {q}^{(w)}=(q,w_q), q\in\mathbb{R}^2, w_q\in\mathbb{R}\) be two weighted points.

The power product, also called power distance between \( {p}^{(w)}\) and \( {q}^{(w)}\) is defined as

\[ \Pi({p}^{(w)},{q}^{(w)}) = {\|{p-q}\|^2-w_p-w_q} \]

where \( \|{p-q}\|\) is the Euclidean distance between \( p\) and \( q\).

The weighted points \( {p}^{(w)}\) and \( {q}^{(w)}\) are said to be orthogonal iff \( \Pi{({p}^{(w)},{q}^{(w)})} = 0\).

Three weighted points have, in 2D, a unique common orthogonal weighted point called the power circle. The power segment will denote the weighted point orthogonal to two weighted points on the line defined by these two points.