`_d_vec_dot_heuristic`

Synopsis#include <flint/d_vec.h>

double _d_vec_dot_heuristic(const double * vec1, const double * vec2, slong len2, double * err)source

Returns the dot product computed by summing the nonnegative and the negative products separately and subtracting the two sums at the end. If err is not NULL, sets *err to $2 n \max(2^{e_p - 53}, 2^{e_q - 53})$ , where $2^{e_p}$ and $2^{e_q}$ bound the two partial sums and $n$ is the length. This is an estimate of the error, not a rigorous bound: it does not account for overflow or underflow, and the factor $2n$ is heuristic for long vectors.

Cite this page

The FLINT team, “_d_vec_dot_heuristic (d_vec.h),” FLINT: Fast Library for Number Theory, documentation, version 3.7.0-dev, 2026. https://flintlib.org/doc/d_vec/_d_vec_dot_heuristic.html (generated 2026-11-02).

@misc{flint-doc-d-vec-d-vec-dot-heuristic,
  author       = {{The FLINT team}},
  title        = {{\_d\_vec\_dot\_heuristic (d\_vec.h)}},
  howpublished = {FLINT: Fast Library for Number Theory, documentation, version 3.7.0-dev},
  year         = {2026},
  url          = {https://flintlib.org/doc/d_vec/_d_vec_dot_heuristic.html},
  note         = {Generated 2026-11-02}
}

Edit this page · PDF version · Built with fdoc from 0a4634bf95