FLINT3.7.0-dev
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_gr_poly_compose, gr_poly_compose, _gr_poly_compose_horner, gr_poly_compose_horner, _gr_poly_compose_divconquer, gr_poly_compose_divconquer

Synopsis#include <flint/gr_poly.h>
int _gr_poly_compose(gr_ptr res, gr_srcptr poly1, slong len1, gr_srcptr poly2, slong len2, gr_ctx_t ctx)source
int gr_poly_compose(gr_poly_t res, const gr_poly_t poly1, const gr_poly_t poly2, gr_ctx_t ctx)source
int _gr_poly_compose_horner(gr_ptr res, gr_srcptr poly1, slong len1, gr_srcptr poly2, slong len2, gr_ctx_t ctx)source
int gr_poly_compose_horner(gr_poly_t res, const gr_poly_t poly1, const gr_poly_t poly2, gr_ctx_t ctx)source
int _gr_poly_compose_divconquer(gr_ptr res, gr_srcptr poly1, slong len1, gr_srcptr poly2, slong len2, gr_ctx_t ctx)source
int gr_poly_compose_divconquer(gr_poly_t res, const gr_poly_t poly1, const gr_poly_t poly2, gr_ctx_t ctx)source

Set res to the composition f(g(x)), where f is poly1 and g is poly2, by Horner's rule or by divide and conquer (splitting f in halves and multiplying by powers of g computed by repeated squaring). The default version handles g = a x^n + c by a Taylor shift by c followed by a scaling and an inflation, uses Horner's rule for \mathit{len1} \le 7 and divide and conquer otherwise. The underscore versions write (\mathit{len1} - 1)(\mathit{len2} - 1) + 1 coefficients and do not allow aliasing.

Cite this page

The FLINT team, “_gr_poly_compose, gr_poly_compose, _gr_poly_compose_horner, gr_poly_compose_horner, _gr_poly_compose_divconquer, gr_poly_compose_divconquer (gr_poly.h),” FLINT: Fast Library for Number Theory, documentation, version 3.7.0-dev, 2026. https://flintlib.org/doc/gr_poly/_gr_poly_compose.html (generated 2026-10-20).