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Updated hypot with simpler formula.

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Added sinh and cosh to ntl.hpp.
Fixed FreeBSD test failures (no real long long support).


[SVN r3598]
This commit is contained in:
John Maddock
2007-01-04 16:20:49 +00:00
parent 2e94601868
commit 27f5e4d59e
16 changed files with 73 additions and 51 deletions
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45
include/boost/math/special_functions/hypot.hpp
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@@ -43,45 +43,12 @@ T hypot(T x, T y)
if(y > x)
(std::swap)(x, y);
//
// Figure out overflow and underflow limits,
// we could make these constants static to save
// a few cycles, but the code would then not be
// thread safe :-(
//
T safe_upper = sqrt(tools::max_value<T>()) / 2;
T safe_lower = sqrt(tools::min_value<T>());
static const T one = 1;
//
// Now handle special cases:
//
if(x >= safe_upper)
{
if(y <= one)
{
// y is negligible:
return x;
}
T a = sqrt(x) * sqrt(y);
T b = sqrt(x/y + y/x);
// We may have overflow:
if(tools::max_value<T>() /a < b)
return tools::overflow_error<T>(BOOST_CURRENT_FUNCTION, 0);
return a * b;
}
else if(y <= safe_lower)
{
if((x >= one) || (y == 0))
{
// y is negligible:
return x;
}
return sqrt(x) * sqrt(y) * sqrt(x/y + y/x);
}
//
// If we get here then x^2+y^2 will not overflow or underflow:
//
return sqrt(x*x + y*y);
if(x * tools::epsilon<T>() >= y)
return x;
T rat = y / x;
return x * sqrt(1 + rat*rat);
} // template <class T> T hypot(T x, T y)

10
include/boost/math/tools/ntl.hpp
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@@ -325,6 +325,16 @@ namespace NTL{
boost::math::tools::digits<NTL::RR>());
}
inline NTL::RR sinh(NTL::RR z)
{
return (expm1(z) - expm1(-z)) / 2;
}
inline NTL::RR cosh(NTL::RR z)
{
return (exp(z) + exp(-z)) / 2;
}
inline NTL::RR fmod(NTL::RR x, NTL::RR y)
{
// This is a really crummy version of fmod, we rely on lots