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Better to_double and to_interval functions

This commit is contained in:
Pedro Machado Manhaes de Castro 2006-06-22 17:30:48 +00:00
parent 07f56c182e
commit 5853c355d3
1 changed files with 34 additions and 12 deletions
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46
Number_types/include/CGAL/MP_Float.h
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@ -414,6 +414,31 @@ to_double(const Root_of_2<MP_Float> &r)
const MP_Float &rc = r[0];
if(is_zero(rc)) {
if(is_negative(rb)) {
if(r.is_smaller()) return 0.0;
std::pair<double, int> pa = to_double_exp(ra);
std::pair<double, int> pb = to_double_exp(rb);
double scale = CGAL_CLIB_STD::ldexp(1.0, pb.second - pa.second);
return -(pb.first / pa.first)*scale;
}
if(r.is_smaller()) {
std::pair<double, int> pa = to_double_exp(ra);
std::pair<double, int> pb = to_double_exp(rb);
double scale = CGAL_CLIB_STD::ldexp(1.0, pb.second - pa.second);
return -(pb.first / pa.first)*scale;
} return 0.0;
}
if(is_zero(rb)) {
std::pair<double, int> pa = to_double_exp(ra);
std::pair<double, int> pc = to_double_exp(rc);
double scale = CGAL_CLIB_STD::ldexp(1.0, pc.second - pa.second);
double m_c_a = -(pc.first / pa.first)*scale;
if(r.is_smaller()) return -std::sqrt(m_c_a);
else return std::sqrt(m_c_a);
}
std::pair<double, int> pa = to_double_exp(ra);
std::pair<double, int> pb = to_double_exp(rb);
std::pair<double, int> pc = to_double_exp(rc);
@ -425,7 +450,7 @@ to_double(const Root_of_2<MP_Float> &r)
double c = CGAL_CLIB_STD::ldexp(pc.first,pc.second);
// Maybe it is better to calculate the delta in Exact Computation
double d = sqrt(square(b) - 4*a*c);
double d = std::sqrt(square(b) - 4*a*c);
if (r.is_smaller())
d = -d;
@ -454,27 +479,24 @@ to_interval(const Root_of_2<MP_Float> &r)
if(r.is_smaller()) return std::make_pair(0.0,0.0);
std::pair<std::pair<double, double>, int> pa = to_interval_exp(ra);
std::pair<std::pair<double, double>, int> pb = to_interval_exp(rb);
Interval_nt<> a = ldexp(Interval_nt<>(pa.first),pa.second);
Interval_nt<> b = ldexp(Interval_nt<>(pb.first),pb.second);
return (-b/a).pair();
return (-ldexp(Interval_nt<>(pb.first) / Interval_nt<>(pa.first),
pb.second - pa.second)).pair();
}
if(r.is_smaller()) {
std::pair<std::pair<double, double>, int> pa = to_interval_exp(ra);
std::pair<std::pair<double, double>, int> pb = to_interval_exp(rb);
Interval_nt<> a = ldexp(Interval_nt<>(pa.first),pa.second);
Interval_nt<> b = ldexp(Interval_nt<>(pb.first),pb.second);
return (-b/a).pair();
return (-ldexp(Interval_nt<>(pb.first) / Interval_nt<>(pa.first),
pb.second - pa.second)).pair();
} return std::make_pair(0.0,0.0);
}
if(is_zero(rb)) {
std::pair<std::pair<double, double>, int> pa = to_interval_exp(ra);
std::pair<std::pair<double, double>, int> pc = to_interval_exp(rc);
Interval_nt<> a = ldexp(Interval_nt<>(pa.first),pa.second);
Interval_nt<> c = ldexp(Interval_nt<>(pc.first),pc.second);
if(r.is_smaller())
return (-CGAL::sqrt(-c/a)).pair();
else return (CGAL::sqrt(-c/a)).pair();
const Interval_nt<> m_c_a = -ldexp(Interval_nt<>(pc.first) / Interval_nt<>(pa.first),
pc.second - pa.second);
if(r.is_smaller()) return (-CGAL::sqrt(m_c_a)).pair();
else return (CGAL::sqrt(m_c_a)).pair();
}
std::pair<std::pair<double, double>, int> pa = to_interval_exp(ra);