Version 5.0 The LEDA User Manual

16.1 Points in 3D-Space ( d3 point )
1. Definition
An instance of the data type d3 point is a point in the three-dimensional space R 3 . We
use (x, y, z) to denote a point with first (or x-) coordinate x, second (or y-) coordinate y,
and third (or z-) coordinate z.
#include < LEDA/geo/d3 point.h >
2. Creation
d3 point p; introduces a variable p of type d3 point initialized to the point
(0, 0, 0).
d3 point
d3 point
p(double x, double y, double z);
p(vector v);
introduces a variable p of type d3 point initialized to the point
(x, y, z).
introduces a variable p of type d3 point initialized to the point
(v[0], v[1], v[2]).
Precondition: v.dim( ) = 3.
3. Operations
double p.xcoord( ) returns the first coordinate of p.
double p.ycoord( ) returns the second coordinate of p.
double p.zcoord( ) returns the third coordinate of p.
vector p.to vector( ) returns the vector xyz. ⃗
point p.project xy( ) returns p projected into the xy-plane.
point p.project yz( ) returns p projected into the yz-plane.
point p.project xz( ) returns p projected into the xz-plane.
double p.sqr dist(const d3 point& q)
double p.xdist(const d3 point& q)
returns the square of the Euclidean distance between p
and q.
returns the x-distance between p and q.