faiss::Score3Computer< Ttab, Taccu > Struct Template Reference

Inheritance diagram for faiss::Score3Computer< Ttab, Taccu >:

Public Member Functions
Taccu	compute (const int *perm) const
Taccu	compute_update (const int *perm, int iw, int jw) const
Taccu	update_i (const int *perm, int iw, int jw, int ip0, int ip, const Ttab *n_gt_i) const
Taccu	update_i_plane (const int *perm, int iw, int jw, int ip0, int ip, const Ttab *n_gt_i) const
Taccu	update_k (const int *perm, int iw, int jw, int ip0, int ip, int jp0, int jp, int k, const Ttab *n_gt_ij) const
	used for the 8 cells were the 3 indices are swapped
Taccu	update_j_line (const int *perm, int iw, int jw, int ip0, int ip, int jp0, int jp, const Ttab *n_gt_ij) const
	compute update on a line of k's, where i and j are swapped
Taccu	update_i_cross (const int *perm, int iw, int jw, int ip0, int ip, const Ttab *n_gt_i) const
	considers the 2 pairs of crossing lines j=iw or jw and k = iw or kw
double	compute_cost (const int *perm) const override
double	cost_update (const int *perm, int iw, int jw) const override

Public Attributes
int	nc
std::vector< Ttab >	n_gt
Public Attributes inherited from faiss::PermutationObjective
int	n

Detailed Description

template<typename Ttab, typename Taccu>
struct faiss::Score3Computer< Ttab, Taccu >

Maintains a 3D table of elementary costs. Accumulates elements based on Hamming distance comparisons

Definition at line 443 of file PolysemousTraining.cpp.

Member Function Documentation

template<typename Ttab, typename Taccu>

Taccu faiss::Score3Computer< Ttab, Taccu >::compute ( const int *  perm ) const

inline

the cost is a triple loop on the nc * nc * nc matrix of entries.

Definition at line 455 of file PolysemousTraining.cpp.

template<typename Ttab, typename Taccu>

double faiss::Score3Computer< Ttab, Taccu >::compute_cost ( const int *  perm ) const

inlineoverridevirtual

PermutationObjective implementeation (just negates the scores for minimization)

Implements faiss::PermutationObjective.

Definition at line 631 of file PolysemousTraining.cpp.

template<typename Ttab, typename Taccu>

Taccu faiss::Score3Computer< Ttab, Taccu >::compute_update ( const int *  perm, int  iw, int  jw  ) const

inline

cost update if entries iw and jw of the permutation would be swapped.

The computation is optimized by avoiding elements in the nc*nc*nc cube that are known not to change. For nc=256, this reduces the nb of cells to visit to about 6/256 th of the cells. Practical speedup is about 8x, and the code is quite complex :-/

Definition at line 486 of file PolysemousTraining.cpp.

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The documentation for this struct was generated from the following file:

• /data/users/matthijs/github_faiss/faiss/PolysemousTraining.cpp