#include "gr_poly.h"
int
_gr_poly_rsqrt_series_generic(gr_ptr res, gr_srcptr f, slong flen, slong len, gr_ctx_t ctx)
{
if (flen <= 8 || ctx->methods[GR_METHOD_POLY_MULLOW] == (gr_funcptr) _gr_poly_mullow_generic)
return _gr_poly_rsqrt_series_basecase(res, f, flen, len, ctx);
else
return _gr_poly_rsqrt_series_newton(res, f, flen, len, FLINT_MIN(10, len / 2), ctx);
}
int
gr_poly_rsqrt_series(gr_poly_t res, const gr_poly_t h, slong len, gr_ctx_t ctx)
{
int status = GR_SUCCESS;
slong hlen;
if (len == 0)
return gr_poly_zero(res, ctx);
hlen = h->length;
if (hlen == 0)
return GR_DOMAIN;
if (hlen == 1)
len = 1;
if (res == h)
{
gr_poly_t t;
gr_poly_init(t, ctx);
status = gr_poly_rsqrt_series(t, h, len, ctx);
gr_poly_swap(res, t, ctx);
gr_poly_clear(t, ctx);
return status;
}
gr_poly_fit_length(res, len, ctx);
status |= _gr_poly_rsqrt_series(res->coeffs, h->coeffs, h->length, len, ctx);
_gr_poly_set_length(res, len, ctx);
_gr_poly_normalise(res, ctx);
return status;
}