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#ifndef MATH_UTILS_H
#define MATH_UTILS_H
#include <math.h>
/* needed for sqrt() below */
#ifdef PREANSI
template <class _Tp>
inline const _Tp& min(const _Tp& __a, const _Tp& __b) {
return __b < __a ? __b : __a;
}
template <class _Tp>
inline const _Tp& max(const _Tp& __a, const _Tp& __b) {
return __a < __b ? __b : __a;
}
#endif
namespace TNT
{
/**
@returns the absolute value of a real (no-complex) scalar.
*/
template <class Real>
Real abs(const Real &a)
{
return (a > 0 ? a : -a);
}
/**
@returns hypotenuse of real (non-complex) scalars a and b by
avoiding underflow/overflow
using (a * sqrt( 1 + (b/a) * (b/a))), rather than
sqrt(a*a + b*b).
*/
template <class Real>
Real hypot(const Real &a, const Real &b)
{
if (a== 0)
return abs(b);
else
{
Real c = b/a;
return a * sqrt(1 + c*c);
}
}
/**
@returns the minimum of scalars a and b.
template <class Scalar>
Scalar min(const Scalar &a, const Scalar &b)
{
return a < b ? a : b;
}
*/
/**
@returns the maximum of scalars a and b.
template <class Scalar>
Scalar max(const Scalar &a, const Scalar &b)
{
return a > b ? a : b;
}
*/
}
#endif
/* MATH_UTILS_H */
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