linbox
1
|
Switching Network based BlackBox Matrix. A good preconditioner. More...
#include <butterfly.h>
Butterfly | |
Butterfly preconditioner and supporting function | |
Butterfly (const Field &F, size_t n, typename Switch::Factory &factory) | |
template<class OutVector , class InVector > | |
OutVector & | apply (OutVector &y, const InVector &x) const |
template<class OutVector , class InVector > | |
OutVector & | applyTranspose (OutVector &y, const InVector &x) const |
Switching Network based BlackBox Matrix. A good preconditioner.
Implements butterfly switching network on a LinBox vector as a black box matrix through the use of a switch object.
This is a blackbox matrix object, and it implements all purely virtual methods of the abstract base class. See BlackboxArchetype} for the specification of these methods.
This matrix requires a dense vector to be used. Sparse vectors must somehow be converted to dense vectors before this matrix may be applied to them.
Vector | LinBox dense vector type |
Switch | switch object type |
Butterfly | ( | const Field & | F, |
size_t | n, | ||
typename Switch::Factory & | factory | ||
) | [inline] |
Constructor from an integer and a switch object. The switch object is an object that is applied to two references to elements to switch them. It must have both an apply and an applyTranspose method. It must contain all information needed by the switch other than the elements themselves. This includes any random numbers or sequences of values. It must also be able to be applied as many times as needed. In particular, it must be able to create new random elements or repeat a stored sequence of values. This is not required by the abstract base class.
n | integer size of vectors to be applied to |
S | switch predicate object object |