1 files changed, 15 insertions, 0 deletions
diff --git a/libtellurian_azimuthal_radius_radians.c b/libtellurian_azimuthal_radius_radians.c
new file mode 100644
index 0000000..00671af
--- /dev/null
+++ b/libtellurian_azimuthal_radius_radians.c
@@ -0,0 +1,15 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+
+
+double
+libtellurian_azimuthal_radius_radians(double latitude, double azimuth)
+{
+	double m = libtellurian_meridan_radius_radians(latitude);
+	double n = libtellurian_transverse_radius_radians(latitude);
+	double c2 = cos(azimuth) * cos(azimuth);
+	double s2 = sin(azimuth) * sin(azimuth);
+	double x = c2 / m;
+	double y = s2 / n;
+	return 1.0 / (x + y);
+}