First commit

Signed-off-by: Mattias Andrée <m@maandree.se>

1 files changed, 14 insertions, 0 deletions

diff --git a/libtellurian_elevated_gravity_radians.c b/libtellurian_elevated_gravity_radians.c
new file mode 100644
index 0000000..ffd1a5b
--- /dev/null
+++ b/libtellurian_elevated_gravity_radians.c
@@ -0,0 +1,14 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+
+
+double
+libtellurian_elevated_gravity_radians(double gravity, double latitude, double altitude)
+{
+	double k1 = -3.1570429877205807e-07;
+	double k2 = 2.1026896504579084e-09;
+	double k3 = -7.374516772941995e-14;
+	double sin2_phi = sin(latitude) * sin(latitude);
+	double f = fma(k3, altitude, fma(k2, sin2_phi, k1));
+	return fma(f * altitude, gravity, gravity);
+}