static void
arb_infimum(arf_t res, const arb_t x)
{
if (arf_is_nan(arb_midref(x)))
{
arf_nan(res);
}
else if (mag_is_inf(arb_radref(x)))
{
arf_neg_inf(res);
}
else
{
arf_set_mag(res, arb_radref(x));
arf_sub(res, arb_midref(x), res, ARF_PREC_EXACT, ARF_RND_FLOOR);
}
}
void
arf_set_fmpr(arf_t y, const fmpr_t x)
{
if (fmpr_is_special(x))
{
if (fmpr_is_zero(x))
arf_zero(y);
else if (fmpr_is_pos_inf(x))
arf_pos_inf(y);
else if (fmpr_is_neg_inf(x))
arf_neg_inf(y);
else
arf_nan(y);
}
else
{
arf_set_fmpz(y, fmpr_manref(x));
fmpz_add_inline(ARF_EXPREF(y), ARF_EXPREF(y), fmpr_expref(x));
}
}
int
arf_sum(arf_t s, arf_srcptr terms, long len, long prec, arf_rnd_t rnd)
{
arf_ptr blocks;
long i, j, used;
int have_merged, res;
/* first check if the result is inf or nan */
{
int have_pos_inf = 0;
int have_neg_inf = 0;
for (i = 0; i < len; i++)
{
if (arf_is_pos_inf(terms + i))
{
if (have_neg_inf)
{
arf_nan(s);
return 0;
}
have_pos_inf = 1;
}
else if (arf_is_neg_inf(terms + i))
{
if (have_pos_inf)
{
arf_nan(s);
return 0;
}
have_neg_inf = 1;
}
else if (arf_is_nan(terms + i))
{
arf_nan(s);
return 0;
}
}
if (have_pos_inf)
{
arf_pos_inf(s);
return 0;
}
if (have_neg_inf)
{
arf_neg_inf(s);
return 0;
}
}
blocks = flint_malloc(sizeof(arf_struct) * len);
for (i = 0; i < len; i++)
arf_init(blocks + i);
/* put all terms into blocks */
used = 0;
for (i = 0; i < len; i++)
{
if (!arf_is_zero(terms + i))
{
arf_set(blocks + used, terms + i);
used++;
}
}
/* merge blocks until all are well separated */
have_merged = 1;
while (used >= 2 && have_merged)
{
have_merged = 0;
for (i = 0; i < used && !have_merged; i++)
{
for (j = i + 1; j < used && !have_merged; j++)
{
if (_arf_are_close(blocks + i, blocks + j, prec))
{
arf_add(blocks + i, blocks + i, blocks + j,
ARF_PREC_EXACT, ARF_RND_DOWN);
/* remove the merged block */
arf_swap(blocks + j, blocks + used - 1);
used--;
/* remove the updated block if the sum is zero */
if (arf_is_zero(blocks + i))
{
arf_swap(blocks + i, blocks + used - 1);
used--;
}
have_merged = 1;
}
}
}
}
if (used == 0)
{
arf_zero(s);
res = 0;
}
else if (used == 1)
{
res = arf_set_round(s, blocks + 0, prec, rnd);
}
else
{
/* find the two largest blocks */
for (i = 1; i < used; i++)
if (arf_cmpabs(blocks + 0, blocks + i) < 0)
arf_swap(blocks + 0, blocks + i);
for (i = 2; i < used; i++)
if (arf_cmpabs(blocks + 1, blocks + i) < 0)
arf_swap(blocks + 1, blocks + i);
res = _arf_add_eps(s, blocks + 0, arf_sgn(blocks + 1), prec, rnd);
}
for (i = 0; i < len; i++)
arf_clear(blocks + i);
flint_free(blocks);
return res;
}
