Version 5.0 The LEDA User Manual

at vector rat vector :: d3(integer a, integer b, integer c, integer D)
rat vector rat vector :: unit(int i, int d = 2)
returns a rat vector of dimension 3 initialized
to a vector with homogeneous representation
(a, b, c, D) if D is positive and representation
(−a, −b, −c, −D) if D is negative.
Precondition: D is non-zero.
returns a rat vector of dimension d initialized
to the i-th unit vector.
Precondition: 0 ≤ i < d.
rat vector
rat vector :: zero(int d = 2) returns the zero vector in d-dimensional
space.
int v.dim( ) returns the dimension of v.
integer v.hcoord(int i) returns the i-th homogeneous coordinate of
v.
rational v.coord(int i) returns the i-th cartesian coordinate of v.
rational v[int i] returns the i-th cartesian coordinate of v.
rational v.sqr length( ) returns the square of the length of v.
vector v.to float( ) returns a floating point approximation of v.
Additional Operations for vectors in two and three-dimensional space
rational v.xcoord( ) returns the zero-th cartesian coordinate of v.
rational v.ycoord( ) returns the first cartesian coordinate of v.
rational v.zcoord( ) returns the second cartesian coordinate of v.
integer v.X( ) returns the zero-th homogeneous coordinate
of v.
integer v.Y( ) returns the first homogeneous coordinate of
v.
integer v.Z( ) returns the second homogeneous coordinate
of v.
integer v.W( ) returns the homogenizing coordinate of v.
rat vector v.rotate90(int i = 1) returns v by an angle of i×90 degrees. If i >
0 the rotation is counter-clockwise otherwise
it is clockwise. Precondition: v.dim( ) == 2.