GRASS GIS 7 Programmer's Manual  7.0.4(2016)-r00000
radii.c
Go to the documentation of this file.
1 
61 #include <math.h>
62 #include <grass/gis.h>
63 #include "pi.h"
64 
80 double G_meridional_radius_of_curvature(double lon, double a, double e2)
81 {
82  double x;
83  double s;
84 
85  s = sin(Radians(lon));
86  x = 1 - e2 * s * s;
87 
88  return a * (1 - e2) / (x * sqrt(x));
89 }
90 
106 double G_transverse_radius_of_curvature(double lon, double a, double e2)
107 {
108  double x;
109  double s;
110 
111  s = sin(Radians(lon));
112  x = 1 - e2 * s * s;
113 
114  return a / sqrt(x);
115 }
116 
133 double G_radius_of_conformal_tangent_sphere(double lon, double a, double e2)
134 {
135  double x;
136  double s;
137 
138  s = sin(Radians(lon));
139  x = 1 - e2 * s * s;
140 
141  return a * sqrt(1 - e2) / x;
142 }
double G_radius_of_conformal_tangent_sphere(double lon, double a, double e2)
Radius of conformal tangent sphere.
Definition: radii.c:133
double G_meridional_radius_of_curvature(double lon, double a, double e2)
Meridional radius of curvature.
Definition: radii.c:80
#define Radians(x)
Definition: pi.h:6
double G_transverse_radius_of_curvature(double lon, double a, double e2)
Transverse radius of curvature.
Definition: radii.c:106