v1.52.0 (#16)

* Add constructor overloads that accept IEllipsoid as parameter for AlbersEqualArea and LambertConformalConic.

* Modify overloads of Forward and Reverse in AlbersEqualArea, AzimuthalEquidistant, CassiniSoldner and LambertConformalConic to return coordinates as tuples.

* Add overloads of Direct and Inverse in Geodesic/GeodesicLine, GeodesicExact/GeodesicLineExact and Rhumb/RhumbLineExact,  that return the computation results as a single object.

* Modify methods using out parameters defined in NormalGravity, GravityModel, GravityCircle, MagneticModel and MagnegticCircle to return results as tuples.

* Enable strong name signing.

* Fix stack overflow bug for Forward and Reverse in TransverseMercatorExact.

* Add definitions of popular reference ellipsoids.

* Update documentation

Author: noelex

GeographicLib/AssemblyInfo.cs

@@ -1,3 +1,3 @@
 using System.Runtime.CompilerServices;
 
-[assembly:InternalsVisibleTo("GeographicLibTests")]
+[assembly:InternalsVisibleTo("GeographicLibTests, PublicKey=002400000480000094000000060200000024000052534131000400000100010075aba3dfe6f7b4a1b3fcd295a4a8652d77e891c02eb11600df39913e623d179a8d3951bea92c6e60733f08d8971270b8e4debb7432935c9c008c5bdfd051bc7e43be4590a81c9f7864fbee1c36481f11aea8f045c95c51779af69cd1c3945ac060d6550bd24b1aadccc2305cbdad75b448997af88d357f90ca97742144b372e8")]

GeographicLib/CMath.cs

@@ -20,12 +20,14 @@ abstract class CMath
 
         public abstract double Frexp(double x, out int e);
 
-#if !NET5_0
+#if !NET5_0_OR_GREATER
         public abstract double CopySign(double x, double y);
 
         public abstract double ScaleB(double number, int exp);
 
         public abstract double FusedMultiplyAdd(double x, double y, double z);
+
+        public abstract double Log2(double x);
 #endif
 
 #if NETSTANDARD2_0

GeographicLib/CMathManaged.cs

@@ -9,7 +9,7 @@
 
 namespace GeographicLib
 {
-#if NET5_0
+#if NET5_0_OR_GREATER
     class CMathNative : CMath
     {
         [ModuleInitializer]
@@ -110,6 +110,9 @@ private class CMathWindows : CMath
             [DllImport(CRuntimeLibrary)]
             private static extern double frexp(double x, out int e);
 
+            [DllImport(CRuntimeLibrary)]
+            public static extern double log2(double x);
+
             public override double Expm1(double x) => expm1(x);
 
             public override double ScaleB(double number, int exp) => scalbn(number, exp);
@@ -126,6 +129,8 @@ private class CMathWindows : CMath
 
             public override double Frexp(double x, out int e) => frexp(x, out e);
 
+            public override double Log2(double x) => log2(x);
+
 #if NETSTANDARD2_0
             [DllImport(CRuntimeLibrary)]
             public static extern double atanh(double x);
@@ -172,6 +177,9 @@ private class CMathLinux : CMath
             [DllImport(CRuntimeLibrary)]
             private static extern double frexp(double x, out int e);
 
+            [DllImport(CRuntimeLibrary)]
+            public static extern double log2(double x);
+
             public override double Expm1(double x) => expm1(x);
 
             public override double ScaleB(double number, int exp) => scalbn(number, exp);
@@ -188,6 +196,8 @@ private class CMathLinux : CMath
 
             public override double Frexp(double x, out int e) => frexp(x, out e);
 
+            public override double Log2(double x) => log2(x);
+
 #if NETSTANDARD2_0
             [DllImport(CRuntimeLibrary)]
             public static extern double atanh(double x);
@@ -234,6 +244,9 @@ private class CMathOSX : CMath
             [DllImport(CRuntimeLibrary)]
             private static extern double frexp(double x, out int e);
 
+            [DllImport(CRuntimeLibrary)]
+            public static extern double log2(double x);
+
             public override double Expm1(double x) => expm1(x);
 
             public override double ScaleB(double number, int exp) => scalbn(number, exp);
@@ -250,6 +263,8 @@ private class CMathOSX : CMath
 
             public override double Frexp(double x, out int e) => frexp(x, out e);
 
+            public override double Log2(double x) => log2(x);
+
 #if NETSTANDARD2_0
             [DllImport(CRuntimeLibrary)]
             public static extern double atanh(double x);

GeographicLib/CMathNative.cs

@@ -64,10 +64,10 @@ public Ellipsoid(double a, double f)
 
         internal Memory<double> RectifyingToConformalCoeffs => _tm._bet;
 
-/// <summary>
-/// Gets a value representing the equatorial radius of the ellipsoid (meters).  This is the value used in the constructor.
-/// </summary>
-public double EquatorialRadius => _a;
+        /// <summary>
+        /// Gets a value representing the equatorial radius of the ellipsoid (meters).  This is the value used in the constructor.
+        /// </summary>
+        public double EquatorialRadius => _a;
 
         /// <summary>
         /// Gets a value representing the polar semi-axis (meters).
@@ -440,7 +440,7 @@ public double TransverseCurvatureRadius(double phi)
         }
 
         /// <summary>
-        /// 
+        /// Calculate the radius of curvature of the ellipsoid in the normal section at specified latitude inclined at specified angle.
         /// </summary>
         /// <param name="phi">the geographic latitude (degrees).</param>
         /// <param name="azi">the angle between the meridian and the normal section (degrees).</param>
@@ -566,9 +566,123 @@ public double NormalCurvatureRadius(double phi, double azi)
         #endregion
 
         /// <summary>
-        /// A global instantiation of Ellipsoid with the parameters for the WGS84 ellipsoid.
+        /// A global instantiation of <see cref="Ellipsoid"/> with the parameters for the WGS-84 (1984) reference ellipsoid.
         /// </summary>
-        /// <returns></returns>
         public static Ellipsoid WGS84 { get; } = new Ellipsoid(Constants.WGS84_a, Constants.WGS84_f);
+
+        /// <summary>
+        /// A global instantiation of <see cref="Ellipsoid"/> with the parameters for the Maupertuis (1738) reference ellipsoid.
+        /// </summary>
+        public static Ellipsoid Maupertuis { get; } = new Ellipsoid(6397300, 1 / 191d);
+
+        /// <summary>
+        /// A global instantiation of <see cref="Ellipsoid"/> with the parameters for the Plessis (1817) reference ellipsoid.
+        /// </summary>
+        public static Ellipsoid Plessis { get; } = new Ellipsoid(6376523, 1 / 308.64);
+
+        /// <summary>
+        /// A global instantiation of <see cref="Ellipsoid"/> with the parameters for the Everest (1830) reference ellipsoid.
+        /// </summary>
+        public static Ellipsoid Everest { get; } = new Ellipsoid(6377299.365, 1 / 300.80172554);
+
+        /// <summary>
+        /// A global instantiation of <see cref="Ellipsoid"/> with the parameters for the Everest 1830 Modified (1967) reference ellipsoid.
+        /// </summary>
+        public static Ellipsoid Everest1830Modified { get; } = new Ellipsoid(6377304.063, 1 / 300.8017);
+
+        /// <summary>
+        /// A global instantiation of <see cref="Ellipsoid"/> with the parameters for the Everest 1830 (1967 Definition) reference ellipsoid.
+        /// </summary>
+        public static Ellipsoid Everest1830 { get; } = new Ellipsoid(6377299.365, 1 / 300.80172554);
+
+        /// <summary>
+        /// A global instantiation of <see cref="Ellipsoid"/> with the parameters for the Airy (1830) reference ellipsoid.
+        /// </summary>
+        public static Ellipsoid Airy { get; } = new Ellipsoid(6377563.396, 1 / 299.3249646);
+
+        /// <summary>
+        /// A global instantiation of <see cref="Ellipsoid"/> with the parameters for the Bessel (1841) reference ellipsoid.
+        /// </summary>
+        public static Ellipsoid Bessel { get; } = new Ellipsoid(6377397.155, 1 / 299.1528128);
+
+        /// <summary>
+        /// A global instantiation of <see cref="Ellipsoid"/> with the parameters for the Clarke (1866) reference ellipsoid.
+        /// </summary>
+        public static Ellipsoid Clarke1866 { get; } = new Ellipsoid(6378206.4, 1 / 294.9786982);
+
+        /// <summary>
+        /// A global instantiation of <see cref="Ellipsoid"/> with the parameters for the Clarke (1878) reference ellipsoid.
+        /// </summary>
+        public static Ellipsoid Clarke1878 { get; } = new Ellipsoid(6378190, 1 / 293.4659980);
+
+        /// <summary>
+        /// A global instantiation of <see cref="Ellipsoid"/> with the parameters for the Clarke (1880) reference ellipsoid.
+        /// </summary>
+        public static Ellipsoid Clarke1880 { get; } = new Ellipsoid(6378249.145, 1 / 293.465);
+
+        /// <summary>
+        /// A global instantiation of <see cref="Ellipsoid"/> with the parameters for the Helmert (1906) reference ellipsoid.
+        /// </summary>
+        public static Ellipsoid Helmert { get; } = new Ellipsoid(6378200, 1 / 298.3);
+
+        /// <summary>
+        /// A global instantiation of <see cref="Ellipsoid"/> with the parameters for the Hayford (1910) reference ellipsoid.
+        /// </summary>
+        public static Ellipsoid Hayford { get; } = new Ellipsoid(6378388, 1 / 297d);
+
+        /// <summary>
+        /// A global instantiation of <see cref="Ellipsoid"/> with the parameters for the International (1924) reference ellipsoid.
+        /// </summary>
+        public static Ellipsoid International { get; } = new Ellipsoid(6378388, 1 / 297d);
+
+        /// <summary>
+        /// A global instantiation of <see cref="Ellipsoid"/> with the parameters for the Krassovsky (1940) reference ellipsoid.
+        /// </summary>
+        public static Ellipsoid Krassovsky { get; } = new Ellipsoid(6378245, 1 / 298.3);
+
+        /// <summary>
+        /// A global instantiation of <see cref="Ellipsoid"/> with the parameters for the WGS66 (1966) reference ellipsoid.
+        /// </summary>
+        public static Ellipsoid WGS66 { get; } = new Ellipsoid(6378145, 1 / 298.25);
+
+        /// <summary>
+        /// A global instantiation of <see cref="Ellipsoid"/> with the parameters for the Australian National (1966) reference ellipsoid.
+        /// </summary>
+        public static Ellipsoid AustralianNational { get; } = new Ellipsoid(6378160, 1 / 298.25);
+
+        /// <summary>
+        /// A global instantiation of <see cref="Ellipsoid"/> with the parameters for the New International (1967) reference ellipsoid.
+        /// </summary>
+        public static Ellipsoid NewInternational { get; } = new Ellipsoid(6378157.5, 1 / 298.24961539);
+
+        /// <summary>
+        /// A global instantiation of <see cref="Ellipsoid"/> with the parameters for the GRS-67 (1967) reference ellipsoid.
+        /// </summary>
+        public static Ellipsoid GRS67 { get; } = new Ellipsoid(6378160, 1 / 298.247167427);
+
+        /// <summary>
+        /// A global instantiation of <see cref="Ellipsoid"/> with the parameters for the South American (1969) reference ellipsoid.
+        /// </summary>
+        public static Ellipsoid SouthAmerican { get; } = new Ellipsoid(6378160, 1 / 298.25);
+
+        /// <summary>
+        /// A global instantiation of <see cref="Ellipsoid"/> with the parameters for the WGS-72 (1972) reference ellipsoid.
+        /// </summary>
+        public static Ellipsoid WGS72 { get; } = new Ellipsoid(6378135, 1 / 298.26);
+
+        /// <summary>
+        /// A global instantiation of <see cref="Ellipsoid"/> with the parameters for the GRS-80 (1979) reference ellipsoid.
+        /// </summary>
+        public static Ellipsoid GRS80 { get; } = new Ellipsoid(6378137, 1 / 298.257222101);
+
+        /// <summary>
+        /// A global instantiation of <see cref="Ellipsoid"/> with the parameters for the IERS (1989) reference ellipsoid.
+        /// </summary>
+        public static Ellipsoid IERS1989 { get; } = new Ellipsoid(6378136, 1 / 298.257);
+
+        /// <summary>
+        /// A global instantiation of <see cref="Ellipsoid"/> with the parameters for the IERS (2003) reference ellipsoid.
+        /// </summary>
+        public static Ellipsoid IERS2003 { get; } = new Ellipsoid(6378136.6, 1 / 298.25642);
     }
 }

GeographicLib/Ellipsoid.cs

@@ -135,12 +135,12 @@ public Geocentric(IEllipsoid ellipsoid) : this(ellipsoid.EquatorialRadius, ellip
         /// <param name="X"><i>x</i> component of geocentric coordinate (meters).</param>
         /// <param name="Y"><i>y</i> component of geocentric coordinate (meters).</param>
         /// <param name="Z"><i>z</i> component of geocentric coordinate (meters).</param>
-        /// <param name="M"> the length of the vector is 9, fill with the rotation matrix in row-major order.</param>
+        /// <param name="M">if the length of the vector is 9, fill with the rotation matrix in row-major order.</param>
         /// <returns>
         /// <list type="bullet">
-        /// <item><i>X</i>, <i>x</i> component of geocentric coordinate (meters).</item>
-        /// <item><i>Y</i>, <i>y</i> component of geocentric coordinate (meters).</item>
-        /// <item><i>Z</i>, <i>z</i> component of geocentric coordinate (meters).</item>
+        /// <item><i>lat</i>, latitude of point (degrees).</item>
+        /// <item><i>lon</i>, longitude of point (degrees).</item>
+        /// <item><i>h</i>, height of point above the ellipsoid (meters).</item>
         /// </list>
         /// </returns>
         /// <remarks>
@@ -164,7 +164,7 @@ public Geocentric(IEllipsoid ellipsoid) : this(ellipsoid.EquatorialRadius, ellip
         /// If there are still multiple solutions with different latitudes (applies only if <i>Z</i> = 0), 
         /// then the solution with <i>lat</i> > 0 is returned.
         /// If there are still multiple solutions with different longitudes (applies only if <i>X</i> = <i>Y</i> = 0)
-        /// then <i>lon</i> = <c>0</c> is returned. The value of h returned satisfies <i>h</i> ≥ − <i>a</i> (1 − <i>e</i>^2) / sqrt(1 − <i>e</i>^2 sin^2<i>lat</i>).
+        /// then <i>lon</i> = <c>0</c> is returned. The value of <i>h</i> returned satisfies <i>h</i> ≥ − <i>a</i> (1 − <i>e</i>^2) / sqrt(1 − <i>e</i>^2 sin^2<i>lat</i>).
         /// The value of lon returned is in the range [−180°, 180°].
         /// </para>
         /// </remarks>
@@ -190,6 +190,20 @@ internal static void Rotate(ReadOnlySpan<double> M,
             Z = M[6] * x + M[7] * y + M[8] * z;
         }
 
+        /// <summary>
+        /// Perform [X,Y,Z]^t = M.[x,y,z]^t (typically local cartesian to geocentric)
+        /// </summary>
+        /// <param name="M"></param>
+        /// <param name="x"></param>
+        /// <param name="y"></param>
+        /// <param name="z"></param>
+        /// <returns></returns>
+        internal static (double X, double Y, double Z) Rotate(ReadOnlySpan<double> M, double x, double y, double z)
+        {
+            Unrotate(M, x, y, z, out var X, out var Y, out var Z);
+            return (X, Y, Z);
+        }
+
         /// <summary>
         /// Perform [x,y,z]^t = M^t.[X,Y,Z]^t (typically geocentric to local cartesian)
         /// </summary>
@@ -209,6 +223,20 @@ internal static void Unrotate(ReadOnlySpan<double> M,
             z = M[2] * X + M[5] * Y + M[8] * Z;
         }
 
+        /// <summary>
+        /// Perform [x,y,z]^t = M^t.[X,Y,Z]^t (typically geocentric to local cartesian)
+        /// </summary>
+        /// <param name="M"></param>
+        /// <param name="X"></param>
+        /// <param name="Y"></param>
+        /// <param name="Z"></param>
+        /// <returns></returns>
+        internal static (double x, double y, double z) Unrotate(ReadOnlySpan<double> M, double X, double Y, double Z)
+        {
+            Unrotate(M, X, Y, Z, out var x, out var y, out var z);
+            return (x, y, z);
+        }
+
         /// <summary>
         /// This rotation matrix is given by the following quaternion operations
         /// qrot(lam, [0,0,1]) * qrot(phi, [0,-1,0]) * [1,1,1,1]/2

GeographicLib/Geocentric.cs

@@ -14,7 +14,7 @@ namespace GeographicLib.Geocodes
     /// The Global Area Reference System is described in
     /// <list type="bullet">
     /// <item><a href="https://en.wikipedia.org/wiki/Global_Area_Reference_System"></a></item>
-    /// <item><a href="http://earth-info.nga.mil/GandG/coordsys/grids/gars.html"></a></item>
+    /// <item><a href="https://earth-info.nga.mil/index.php?dir=coordsys&amp;action=coordsys#tab_gars"></a></item>
     /// </list>
     /// <para>
     /// It provides a compact string representation of a geographic area (expressed as latitude and longitude).

GeographicLib/Geocodes/GARS.cs

@@ -14,7 +14,7 @@ namespace GeographicLib.Geocodes
     /// The World Geographic Reference System is described in
     /// <list type="bullet">
     /// <item><a href="https://en.wikipedia.org/wiki/Georef"></a></item>
-    /// <item><a href="http://earth-info.nga.mil/GandG/coordsys/grids/georef.pdf"></a></item>
+    /// <item><a href="https://web.archive.org/web/20161214054445/http://earth-info.nga.mil/GandG/coordsys/grids/georef.pdf"></a></item>
     /// </list>
     /// <para>
     /// It provides a compact string representation of a geographic area (expressed as latitude and longitude).