functions.h File Reference

#include <cmath>
#include <cstdint>
#include "gromacs/utility/gmxassert.h"
#include "gromacs/utility/real.h"

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Description

Declares simple math functions.

Author

Erik Lindahl erik..nosp@m.lind.nosp@m.ahl@g.nosp@m.mail.nosp@m..com

Classes
struct	gmx::StaticLog2< n >
	Evaluate log2(n) for integer n statically at compile time. More...
struct	gmx::StaticLog2< 1 >
	Specialization of StaticLog2<n> for n==1. More...
struct	gmx::StaticLog2< 0 >
	Specialization of StaticLog2<n> for n==0. More...

Functions
unsigned int	gmx::log2I (std::int32_t x)
	Compute floor of logarithm to base 2, 32 bit signed argument. More...
unsigned int	gmx::log2I (std::int64_t x)
	Compute floor of logarithm to base 2, 64 bit signed argument. More...
unsigned int	gmx::log2I (std::uint32_t x)
	Compute floor of logarithm to base 2, 32 bit unsigned argument. More...
unsigned int	gmx::log2I (std::uint64_t x)
	Compute floor of logarithm to base 2, 64 bit unsigned argument. More...
std::int64_t	gmx::greatestCommonDivisor (std::int64_t p, std::int64_t q)
	Find greatest common divisor of two numbers. More...
static float	gmx::invsqrt (float x)
	Calculate 1.0/sqrt(x) in single precision. More...
static double	gmx::invsqrt (double x)
	Calculate 1.0/sqrt(x) in double precision, but single range. More...
static double	gmx::invsqrt (int x)
	Calculate 1.0/sqrt(x) for integer x in double precision. More...
static float	gmx::invcbrt (float x)
	Calculate inverse cube root of x in single precision. More...
static double	gmx::invcbrt (double x)
	Calculate inverse sixth root of x in double precision. More...
static double	gmx::invcbrt (int x)
	Calculate inverse sixth root of integer x in double precision. More...
static float	gmx::sixthroot (float x)
	Calculate sixth root of x in single precision. More...
static double	gmx::sixthroot (double x)
	Calculate sixth root of x in double precision. More...
static double	gmx::sixthroot (int x)
	Calculate sixth root of integer x, return double. More...
static float	gmx::invsixthroot (float x)
	Calculate inverse sixth root of x in single precision. More...
static double	gmx::invsixthroot (double x)
	Calculate inverse sixth root of x in double precision. More...
static double	gmx::invsixthroot (int x)
	Calculate inverse sixth root of integer x in double precision. More...
template<typename T >
T	gmx::square (T x)
	calculate x^2 More...
template<typename T >
T	gmx::power3 (T x)
	calculate x^3 More...
template<typename T >
T	gmx::power4 (T x)
	calculate x^4 More...
template<typename T >
T	gmx::power5 (T x)
	calculate x^5 More...
template<typename T >
T	gmx::power6 (T x)
	calculate x^6 More...
template<typename T >
T	gmx::power12 (T x)
	calculate x^12 More...
static real	gmx::series_sinhx (real x)
	Maclaurin series for sinh(x)/x. More...
double	gmx::erfinv (double x)
	Inverse error function, double precision. More...
float	gmx::erfinv (float x)
	Inverse error function, single precision. More...
constexpr int32_t	gmx::exactDiv (int32_t a, int32_t b)
	Exact integer division, 32bit. More...
constexpr int64_t	gmx::exactDiv (int64_t a, int64_t b)
	Exact integer division, 64bit.
static int	gmx::roundToInt (float x)
	Round float to int. More...
static int	gmx::roundToInt (double x)
	Round double to int.
static int64_t	gmx::roundToInt64 (float x)
	Round float to int64_t.
static int64_t	gmx::roundToInt64 (double x)
	Round double to int64_t.
template<typename T , typename = std::enable_if_t<std::is_integral<T>::value>>
static constexpr bool	gmx::isPowerOfTwo (const T v)
	Check whether v is an integer power of 2.