Regina Calculation Engine
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A fast class for storing a ray rooted at the origin whose coordinates are rational. More...
#include <maths/nray.h>
Public Member Functions | |
NRay (unsigned length) | |
Creates a new ray all of whose coordinates are initialised to zero. | |
NRay (const NVector< NLargeInteger > &cloneMe) | |
Creates a new ray that is a clone of the given ray. | |
void | scaleDown () |
Scales this vector down by the greatest common divisor of all its elements. | |
void | negate () |
Negates every element of this vector. |
A fast class for storing a ray rooted at the origin whose coordinates are rational.
Such a ray is a half-line beginning at the origin and is represented by an integer point that it passes through. Positive scalar multiples of a ray are considered to represent the same ray.
This class is intended for serious computation, and as a result it has a streamlined implementation with no virtual methods. It can be subclassed, but since there are no virtual methods, type information must generally be known at compile time. Nevertheless, in many respects, different subclasses of NRay can happily interact with one another.
regina::NRay::NRay | ( | unsigned | length | ) | [inline] |
Creates a new ray all of whose coordinates are initialised to zero.
length | the number of elements in the new vector. |
regina::NRay::NRay | ( | const NVector< NLargeInteger > & | cloneMe | ) | [inline] |
Creates a new ray that is a clone of the given ray.
cloneMe | the ray to clone. |
void regina::NRay::negate | ( | ) | [inline] |
Negates every element of this vector.
Reimplemented from regina::NVector< NLargeInteger >.
void regina::NRay::scaleDown | ( | ) |
Scales this vector down by the greatest common divisor of all its elements.
The resulting vector will be the smallest multiple of the original that maintains integral entries, and these entries will have the same signs as the originals.
This routine thus reduces a ray to its smallest possible representation.
This routine poses no problem for vectors containing infinite elements; such elements are simply ignored and left at infinity.