#include <VectorTransform.h>
Public Member Functions | |
| PCAMatrix (int d_in=0, int d_out=0, float eigen_power=0, bool random_rotation=false) | |
| virtual void | train (Index::idx_t n, const float *x) override |
| virtual void | reverse_transform (idx_t n, const float *xt, float *x) const override |
| void | copy_from (const PCAMatrix &other) |
| copy pre-trained PCA matrix | |
| void | prepare_Ab () |
| called after mean, PCAMat and eigenvalues are computed | |
Public Member Functions inherited from faiss::LinearTransform | |
| LinearTransform (int d_in=0, int d_out=0, bool have_bias=false) | |
| both d_in > d_out and d_out < d_in are supported | |
| virtual void | apply_noalloc (idx_t n, const float *x, float *xt) const |
| same as apply, but result is pre-allocated | |
| void | transform_transpose (idx_t n, const float *y, float *x) const |
| const float * | maybe_subsample_train_set (Index::idx_t *n, const float *x) |
Public Member Functions inherited from faiss::VectorTransform | |
| VectorTransform (int d_in=0, int d_out=0) | |
| ! output dimension | |
| float * | apply (idx_t n, const float *x) const |
Public Attributes | |
| float | eigen_power |
| bool | random_rotation |
| random rotation after PCA | |
| int | balanced_bins |
| try to distribute output eigenvectors in this many bins | |
| std::vector< float > | mean |
| Mean, size d_in. | |
| std::vector< float > | eigenvalues |
| eigenvalues of covariance matrix (= squared singular values) | |
| std::vector< float > | PCAMat |
| PCA matrix, size d_in * d_in. | |
Public Attributes inherited from faiss::LinearTransform | |
| bool | have_bias |
| std::vector< float > | A |
| ! whether to use the bias term More... | |
| std::vector< float > | b |
| bias vector, size d_out | |
| size_t | max_points_per_d |
| bool | verbose |
Public Attributes inherited from faiss::VectorTransform | |
| int | d_in |
| int | d_out |
| ! input dimension | |
| bool | is_trained |
Additional Inherited Members | |
Public Types inherited from faiss::VectorTransform | |
| typedef Index::idx_t | idx_t |
Applies a principal component analysis on a set of vectors, with optionally whitening and random rotation.
Definition at line 136 of file VectorTransform.h.
|
overridevirtual |
reverse transformation. May not be implemented or may return approximate result
Reimplemented from faiss::VectorTransform.
Definition at line 444 of file VectorTransform.cpp.
|
overridevirtual |
Perform training on a representative set of vectors. Does nothing by default.
| n | nb of training vectors |
| x | training vecors, size n * d |
Reimplemented from faiss::VectorTransform.
Definition at line 227 of file VectorTransform.cpp.
| float faiss::PCAMatrix::eigen_power |
after transformation the components are multiplied by eigenvalues^eigen_power
=0: no whitening =-2: full whitening
Definition at line 144 of file VectorTransform.h.
1.8.5