Computes a residual vector after indexing encoding.
The residual vector is the difference between a vector and the
reconstruction that can be decoded from its representation in
the index. The residual can be used for multiple-stage indexing
methods, like IndexIVF's methods.
@param index opaque pointer to index object
@param x input vector, size d
@param residual output residual vector, size d
@param key encoded index, as returned by search and assign
Computes a residual vector after indexing encoding.
The residual vector is the difference between a vector and the reconstruction that can be decoded from its representation in the index. The residual can be used for multiple-stage indexing methods, like IndexIVF's methods.
@param index opaque pointer to index object @param x input vector, size d @param residual output residual vector, size d @param key encoded index, as returned by search and assign