1 files changed, 17 insertions, 0 deletions
diff --git a/libtellurian_sea_level_radians.c b/libtellurian_sea_level_radians.c
new file mode 100644
index 0000000..a23b222
--- /dev/null
+++ b/libtellurian_sea_level_radians.c
@@ -0,0 +1,17 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+
+
+double
+libtellurian_sea_level_radians(double latitude)
+{
+	double a = LIBTELLURIAN_EQUATORIAL_RADIUS;
+	double b = LIBTELLURIAN_POLAR_RADIUS;
+	double c = cos(latitude);
+	double s = sin(latitude);
+	double x = a * c * a;
+	double y = b * s * b;
+	double num = fma(x, x, y * y);
+	double denom = fma(x, c, y * s);
+	return sqrt(num / denom);
+}