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/* See LICENSE file for copyright and license details. */
#include "common.h"
#ifndef TEST
double
libtellurian_meridian_radius_radians(double latitude)
{
double a = LIBTELLURIAN_EQUATORIAL_RADIUS;
double b = LIBTELLURIAN_POLAR_RADIUS;
double neg_e2 = fma(b / a, b / a, -1.0);
double s = sin(latitude);
return fma(a, neg_e2, a) / pow(fma(neg_e2, s * s, 1.0), 1.5);
}
#else
static int
approx(double a, double b)
{
return fabs(a - b) <= 1e-8 * (0.5 * (a + b));
}
int
main(void)
{
double x = 0.9933056200098025 * LIBTELLURIAN_EQUATORIAL_RADIUS;
ASSERT(fabs(libtellurian_meridian_radius_radians(0) - x) / x < 1.0e-8);
ASSERT(approx(libtellurian_meridian_radius_radians(D30), libtellurian_meridian_radius_radians(-D30)));
ASSERT(approx(libtellurian_meridian_radius_radians(D45), libtellurian_meridian_radius_radians(-D45)));
ASSERT(approx(libtellurian_meridian_radius_radians(D60), libtellurian_meridian_radius_radians(-D60)));
ASSERT(approx(libtellurian_meridian_radius_radians(D90), libtellurian_meridian_radius_radians(-D90)));
ASSERT(approx(libtellurian_meridian_radius_radians(D180), libtellurian_meridian_radius_radians(0)));
ASSERT(approx(libtellurian_meridian_radius_radians(-D180), libtellurian_meridian_radius_radians(0)));
ASSERT(approx(libtellurian_meridian_radius_radians(D90 + D180), libtellurian_meridian_radius_radians(D90)));
ASSERT(approx(libtellurian_meridian_radius_radians(-D90), libtellurian_meridian_radius_radians(D90)));
ASSERT(fabs(libtellurian_meridian_radius_radians(D90) - 6399593.625758674) / 6399593.625758674 < 1.0e-8);
ASSERT(fabs(libtellurian_meridian_radius_radians(D30) - 6351377.103715289) / 6351377.103715289 < 1.0e-8);
return 0;
}
#endif
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