Download or view Datum.frink in plain text format
// References:
// http://www.uwgb.edu/dutchs/UsefulData/UTMFormulas.HTM
// This represents the shape of the spheroid in a geographic datum.
// It also calculates features of each datum so they can be addressed
// as member variables.
//
// NOTE: Please ensure that you have the 2006-05-16 or later release of Frink
// as previous versions do not handle cyclical class definitions properly.
class Datum
{
// The name of the datum/projection
var name
// Equatorial radius (generally called "a" in calculations so this
// makes it easier to write.
var a
// Polar radius (generally called "a" in calculations so this
// makes it easier to write.
var b
// Eccentricity
var e
// eprime is another eccentricity value. It is only used as squares,
// fourth powers, sixth, etc., but it is stored here as the first power.
var eprime
// The "flattening" of the sphere
var flattening
var n
// Constructor
new[dName is string, equatorialRadius is length, polarRadius is length] :=
{
name = dName
a = equatorialRadius
b = polarRadius
// Calculate other values
e = sqrt[1-b^2/a^2]
eprime = e a / b
n = (a-b)/(a+b)
flattening = (a-b)/a
}
// Make common datums.
class var WGS84 = new Datum["WGS84", 6378137 m, 6356752.3142 m]
class var NAD83 = new Datum["NAD83", 6378137 m, 6356752.3142 m]
class var GRS80 = new Datum["GRS 80",6378137 m, 6356752.3141 m]
class var WGS72 = new Datum["WGS72", 6378135 m, 6356750.5 m]
class var Australian1965 = new Datum["Australian 1965",
6378160 m, 6356774.7 m]
class var Krasovsky1940 = new Datum["Krasovsky 1940",
6378245 m, 6356863.0 m]
class var Hayford1909 = new Datum["Hayford 1909", 6378388 m, 6356911.9 m]
class var Clake1880 = new Datum["Clake 1880", 6378249.1 m, 6356514.9 m]
class var Clarke1866 = new Datum["Clarke 1866", 6378206.4 m, 6356583.8 m]
class var Airy1830 = new Datum["Airy 1830", 6377563.4 m, 6356256.9 m]
class var Bessel1841 = new Datum["Bessel 1841", 6377397.2 m, 6356079.0 m]
class var Everest1830 = new Datum["Everest 1830", 6377276.3 m, 6356075.4 m]
}
"Datum.frink included"
Download or view Datum.frink in plain text format
This is a program written in the programming language Frink.
For more information, view the Frink
Documentation or see More Sample Frink Programs.
Alan Eliasen was born 19972 days, 23 hours, 36 minutes ago.