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repair asin and acos on complex numbers (though why the old algorithm was wrong is frankly beyond me)

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svn: r11196
This commit is contained in:
Matthew Flatt 2008-08-12 00:42:25 +00:00
parent 717895e087
commit ea8c4b3f38
1 changed files with 20 additions and 16 deletions
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36
src/mzscheme/src/number.c
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@ -1511,6 +1511,7 @@ static Scheme_Object *complex_tan(Scheme_Object *c)
}
static Scheme_Object *complex_asin(Scheme_Object *c);
static Scheme_Object *complex_atan(Scheme_Object *c);
static Scheme_Object *complex_asin(Scheme_Object *c)
{
@ -1519,30 +1520,33 @@ static Scheme_Object *complex_asin(Scheme_Object *c)
one_minus_c_sq = scheme_bin_minus(scheme_make_integer(1),
scheme_bin_mult(c, c));
sqrt_1_minus_c_sq = scheme_sqrt(1, &one_minus_c_sq);
return scheme_bin_mult(scheme_minus_i,
un_log(scheme_bin_plus(scheme_bin_mult(c, scheme_plus_i),
sqrt_1_minus_c_sq)));
return scheme_bin_mult(scheme_make_integer(2),
complex_atan(scheme_bin_div(c,
scheme_bin_plus(scheme_make_integer(1),
sqrt_1_minus_c_sq))));
}
static Scheme_Object *complex_acos(Scheme_Object *c);
static Scheme_Object *complex_acos(Scheme_Object *c)
{
Scheme_Object *one_minus_c_sq, *sqrt_1_minus_c_sq;
one_minus_c_sq = scheme_bin_minus(scheme_make_integer(1),
scheme_bin_mult(c, c));
sqrt_1_minus_c_sq = scheme_sqrt(1, &one_minus_c_sq);
return scheme_bin_mult(scheme_minus_i,
un_log(scheme_bin_plus(c,
scheme_bin_mult(scheme_plus_i,
sqrt_1_minus_c_sq))));
Scheme_Object *a, *r;
a = complex_asin(c);
if (scheme_is_zero(_scheme_complex_imaginary_part(c))
&& (scheme_bin_gt(_scheme_complex_real_part(c), scheme_make_integer(1))
|| scheme_bin_lt(_scheme_complex_real_part(c), scheme_make_integer(-1)))) {
/* Make sure real part is 0 or pi */
if (scheme_is_negative(_scheme_complex_real_part(c)))
r = scheme_pi;
else
r = scheme_make_integer(0);
return scheme_make_complex(r, scheme_bin_minus(scheme_make_integer(0),
_scheme_complex_imaginary_part(a)));
} else {
return scheme_bin_minus(scheme_half_pi, a);
}
}
static Scheme_Object *complex_atan(Scheme_Object *c);
static Scheme_Object *complex_atan(Scheme_Object *c)
{
if (scheme_complex_eq(c, scheme_plus_i) || scheme_complex_eq(c, scheme_minus_i))