#include "gr_special.h"
#include "gr_vec.h"
#include "gr_poly.h"
int
_gr_poly_tan_series_basecase(gr_ptr g, gr_srcptr h, slong hlen, slong len, gr_ctx_t ctx)
{
slong sz = ctx->sizeof_elem;
int status = GR_SUCCESS;
hlen = FLINT_MIN(hlen, len);
if (hlen == 1)
{
status |= gr_tan(g, h, ctx);
status |= _gr_vec_zero(GR_ENTRY(g, 1, sz), len - 1, ctx);
}
else if (len == 2)
{
gr_ptr t;
GR_TMP_INIT(t, ctx);
status |= gr_tan(g, h, ctx);
status |= gr_mul(t, g, g, ctx);
status |= gr_add_ui(t, t, 1, ctx);
status |= gr_mul(GR_ENTRY(g, 1, sz), t, GR_ENTRY(h, 1, sz), ctx);
GR_TMP_CLEAR(t, ctx);
}
else
{
gr_ptr t, u;
GR_TMP_INIT_VEC(t, 2 * len, ctx);
u = GR_ENTRY(t, len, sz);
status |= _gr_poly_sin_cos_series_basecase(t, u, h, hlen, len, 0, ctx);
status |= _gr_poly_div_series(g, t, len, u, len, len, ctx);
GR_TMP_CLEAR_VEC(t, 2 * len, ctx);
}
return status;
}
int
gr_poly_tan_series_basecase(gr_poly_t res, const gr_poly_t f, slong len, gr_ctx_t ctx)
{
slong flen = f->length;
int status = GR_SUCCESS;
if (flen == 0 || len == 0)
return gr_poly_zero(res, ctx);
if (flen == 1)
len = 1;
gr_poly_fit_length(res, len, ctx);
status |= _gr_poly_tan_series_basecase(res->coeffs, f->coeffs, flen, len, ctx);
_gr_poly_set_length(res, len, ctx);
_gr_poly_normalise(res, ctx);
return status;
}