GeographicLib  1.52
GeographicLib::Constants Class Reference

Constants needed by GeographicLib More...

#include <GeographicLib/Constants.hpp>

Static Public Member Functions

static Math::real degree ()
 
static Math::real arcminute ()
 
static Math::real arcsecond ()
 
Ellipsoid parameters
template<typename T = real>
static T WGS84_a ()
 
template<typename T = real>
static T WGS84_f ()
 
template<typename T = real>
static T WGS84_GM ()
 
template<typename T = real>
static T WGS84_omega ()
 
template<typename T = real>
static T GRS80_a ()
 
template<typename T = real>
static T GRS80_GM ()
 
template<typename T = real>
static T GRS80_omega ()
 
template<typename T = real>
static T GRS80_J2 ()
 
template<typename T = real>
static T UTM_k0 ()
 
template<typename T = real>
static T UPS_k0 ()
 
SI units
template<typename T = real>
static T meter ()
 
static Math::real kilometer ()
 
static Math::real nauticalmile ()
 
template<typename T = real>
static T square_meter ()
 
static Math::real hectare ()
 
static Math::real square_kilometer ()
 
static Math::real square_nauticalmile ()
 
Anachronistic British units
static Math::real foot ()
 
static Math::real yard ()
 
static Math::real fathom ()
 
static Math::real chain ()
 
static Math::real furlong ()
 
static Math::real mile ()
 
static Math::real acre ()
 
static Math::real square_mile ()
 
Anachronistic US units
static Math::real surveyfoot ()
 

Related Functions

(Note that these are not member functions.)

#define GEOGRAPHICLIB_VERSION_NUM(a, b, c)   ((((a) * 10000 + (b)) * 100) + (c))
 
#define GEOGRAPHICLIB_VERSION
 

Detailed Description

Constants needed by GeographicLib

Define constants specifying the WGS84 ellipsoid, the UTM and UPS projections, and various unit conversions.

Example of use:

// Example of using the GeographicLib::Constants class
#include <iostream>
#include <exception>
using namespace std;
using namespace GeographicLib;
int main() {
try {
cout << "WGS84 parameters:\n"
<< "a = " << Constants::WGS84_a() << " m\n"
<< "f = 1/" << 1/Constants::WGS84_f() << "\n";
}
catch (const exception& e) {
cerr << "Caught exception: " << e.what() << "\n";
return 1;
}
}
int main(int argc, const char *const argv[])
Definition: CartConvert.cpp:29
Header for GeographicLib::Constants class.
Namespace for GeographicLib.
Definition: Accumulator.cpp:12

Definition at line 106 of file Constants.hpp.

Member Function Documentation

◆ degree()

static Math::real GeographicLib::Constants::degree ( )
inlinestatic

A synonym for Math::degree<real>().

Definition at line 115 of file Constants.hpp.

References GeographicLib::Math::degree().

◆ arcminute()

static Math::real GeographicLib::Constants::arcminute ( )
inlinestatic
Returns
the number of radians in an arcminute.

Definition at line 119 of file Constants.hpp.

References GeographicLib::Math::degree().

◆ arcsecond()

static Math::real GeographicLib::Constants::arcsecond ( )
inlinestatic
Returns
the number of radians in an arcsecond.

Definition at line 124 of file Constants.hpp.

References GeographicLib::Math::degree().

◆ WGS84_a()

◆ WGS84_f()

◆ WGS84_GM()

template<typename T = real>
static T GeographicLib::Constants::WGS84_GM ( )
inlinestatic
Template Parameters
Tthe type of the returned value.
Returns
the gravitational constant of the WGS84 ellipsoid, GM, in m3 s−2.

Definition at line 151 of file Constants.hpp.

Referenced by GeographicLib::NormalGravity::WGS84().

◆ WGS84_omega()

template<typename T = real>
static T GeographicLib::Constants::WGS84_omega ( )
inlinestatic
Template Parameters
Tthe type of the returned value.
Returns
the angular velocity of the WGS84 ellipsoid, ω, in rad s−1.

Definition at line 158 of file Constants.hpp.

Referenced by GeographicLib::NormalGravity::WGS84().

◆ GRS80_a()

template<typename T = real>
static T GeographicLib::Constants::GRS80_a ( )
inlinestatic
Template Parameters
Tthe type of the returned value.
Returns
the equatorial radius of GRS80 ellipsoid, a, in m.

Definition at line 164 of file Constants.hpp.

Referenced by GeographicLib::NormalGravity::GRS80().

◆ GRS80_GM()

template<typename T = real>
static T GeographicLib::Constants::GRS80_GM ( )
inlinestatic
Template Parameters
Tthe type of the returned value.
Returns
the gravitational constant of the GRS80 ellipsoid, GM, in m3 s−2.

Definition at line 171 of file Constants.hpp.

Referenced by GeographicLib::NormalGravity::GRS80().

◆ GRS80_omega()

template<typename T = real>
static T GeographicLib::Constants::GRS80_omega ( )
inlinestatic
Template Parameters
Tthe type of the returned value.
Returns
the angular velocity of the GRS80 ellipsoid, ω, in rad s−1.

This is about 2 π 366.25 / (365.25 × 24 × 3600) rad s−1. 365.25 is the number of days in a Julian year and 365.35/366.25 converts from solar days to sidereal days. Using the number of days in a Gregorian year (365.2425) results in a worse approximation (because the Gregorian year includes the precession of the earth's axis).

Definition at line 185 of file Constants.hpp.

Referenced by GeographicLib::NormalGravity::GRS80().

◆ GRS80_J2()

template<typename T = real>
static T GeographicLib::Constants::GRS80_J2 ( )
inlinestatic
Template Parameters
Tthe type of the returned value.
Returns
the dynamical form factor of the GRS80 ellipsoid, J2.

Definition at line 192 of file Constants.hpp.

Referenced by GeographicLib::NormalGravity::GRS80().

◆ UTM_k0()

template<typename T = real>
static T GeographicLib::Constants::UTM_k0 ( )
inlinestatic
Template Parameters
Tthe type of the returned value.
Returns
the central scale factor for UTM (0.9996).

Definition at line 198 of file Constants.hpp.

Referenced by main(), GeographicLib::TransverseMercator::UTM(), and GeographicLib::TransverseMercatorExact::UTM().

◆ UPS_k0()

template<typename T = real>
static T GeographicLib::Constants::UPS_k0 ( )
inlinestatic
Template Parameters
Tthe type of the returned value.
Returns
the central scale factor for UPS (0.994).

Definition at line 204 of file Constants.hpp.

Referenced by GeographicLib::PolarStereographic::UPS().

◆ meter()

template<typename T = real>
static T GeographicLib::Constants::meter ( )
inlinestatic
Template Parameters
Tthe type of the returned value.
Returns
the number of meters in a meter.

This is unity, but this lets the internal system of units be changed if necessary.

Definition at line 218 of file Constants.hpp.

◆ kilometer()

static Math::real GeographicLib::Constants::kilometer ( )
inlinestatic
Returns
the number of meters in a kilometer.

Definition at line 222 of file Constants.hpp.

◆ nauticalmile()

static Math::real GeographicLib::Constants::nauticalmile ( )
inlinestatic
Returns
the number of meters in a nautical mile (approximately 1 arc minute)

Definition at line 228 of file Constants.hpp.

◆ square_meter()

template<typename T = real>
static T GeographicLib::Constants::square_meter ( )
inlinestatic
Template Parameters
Tthe type of the returned value.
Returns
the number of square meters in a square meter.

This is unity, but this lets the internal system of units be changed if necessary.

Definition at line 238 of file Constants.hpp.

◆ hectare()

static Math::real GeographicLib::Constants::hectare ( )
inlinestatic
Returns
the number of square meters in a hectare.

Definition at line 243 of file Constants.hpp.

◆ square_kilometer()

static Math::real GeographicLib::Constants::square_kilometer ( )
inlinestatic
Returns
the number of square meters in a square kilometer.

Definition at line 248 of file Constants.hpp.

◆ square_nauticalmile()

static Math::real GeographicLib::Constants::square_nauticalmile ( )
inlinestatic
Returns
the number of square meters in a square nautical mile.

Definition at line 253 of file Constants.hpp.

◆ foot()

static Math::real GeographicLib::Constants::foot ( )
inlinestatic
Returns
the number of meters in an international foot.

Definition at line 263 of file Constants.hpp.

◆ yard()

static Math::real GeographicLib::Constants::yard ( )
inlinestatic
Returns
the number of meters in a yard.

Definition at line 268 of file Constants.hpp.

◆ fathom()

static Math::real GeographicLib::Constants::fathom ( )
inlinestatic
Returns
the number of meters in a fathom.

Definition at line 272 of file Constants.hpp.

◆ chain()

static Math::real GeographicLib::Constants::chain ( )
inlinestatic
Returns
the number of meters in a chain.

Definition at line 276 of file Constants.hpp.

◆ furlong()

static Math::real GeographicLib::Constants::furlong ( )
inlinestatic
Returns
the number of meters in a furlong.

Definition at line 280 of file Constants.hpp.

◆ mile()

static Math::real GeographicLib::Constants::mile ( )
inlinestatic
Returns
the number of meters in a statute mile.

Definition at line 284 of file Constants.hpp.

◆ acre()

static Math::real GeographicLib::Constants::acre ( )
inlinestatic
Returns
the number of square meters in an acre.

Definition at line 288 of file Constants.hpp.

◆ square_mile()

static Math::real GeographicLib::Constants::square_mile ( )
inlinestatic
Returns
the number of square meters in a square statute mile.

Definition at line 292 of file Constants.hpp.

◆ surveyfoot()

static Math::real GeographicLib::Constants::surveyfoot ( )
inlinestatic
Returns
the number of meters in a US survey foot.

Definition at line 301 of file Constants.hpp.

Friends And Related Function Documentation

◆ GEOGRAPHICLIB_VERSION_NUM

#define GEOGRAPHICLIB_VERSION_NUM (   a,
  b,
 
)    ((((a) * 10000 + (b)) * 100) + (c))
related

Pack the version components into a single integer. Users should not rely on this particular packing of the components of the version number; see the documentation for GEOGRAPHICLIB_VERSION, below.

Definition at line 21 of file Constants.hpp.

◆ GEOGRAPHICLIB_VERSION

#define GEOGRAPHICLIB_VERSION
related
Value:
GEOGRAPHICLIB_VERSION_NUM(GEOGRAPHICLIB_VERSION_MAJOR, \
GEOGRAPHICLIB_VERSION_MINOR, \
GEOGRAPHICLIB_VERSION_PATCH)
#define GEOGRAPHICLIB_VERSION_NUM(a, b, c)
Definition: Constants.hpp:21

The version of GeographicLib as a single integer, packed as MMmmmmpp where MM is the major version, mmmm is the minor version, and pp is the patch level. Users should not rely on this particular packing of the components of the version number. Instead they should use a test such as

#if GEOGRAPHICLIB_VERSION >= GEOGRAPHICLIB_VERSION_NUM(1,37,0)
...
#endif

Definition at line 34 of file Constants.hpp.


The documentation for this class was generated from the following file: