diff options
Diffstat (limited to '')
| -rw-r--r-- | libtellurian_coarse_distance_radians.c | 44 |
1 files changed, 43 insertions, 1 deletions
diff --git a/libtellurian_coarse_distance_radians.c b/libtellurian_coarse_distance_radians.c index eb9cac0..f22ad28 100644 --- a/libtellurian_coarse_distance_radians.c +++ b/libtellurian_coarse_distance_radians.c @@ -1,6 +1,10 @@ /* See LICENSE file for copyright and license details. */ #include "common.h" +#define R LIBTELLURIAN_AUTHALIC_RADIUS + +#ifndef TEST + double libtellurian_coarse_distance_radians(double latitude1, double longitude1, @@ -9,5 +13,43 @@ libtellurian_coarse_distance_radians(double latitude1, double longitude1, double h = fma(haversin(longitude2 - longitude1), cos(latitude1) * cos(latitude2), haversin(latitude2 - latitude1)); - return 2.0 * LIBTELLURIAN_AUTHALIC_RADIUS * asin(sqrt(h)); + return 2.0 * R * asin(sqrt(h)); } + + +#else + + +static int +check(double a, double b, double c, double d, double expect) +{ + double got = libtellurian_coarse_distance_radians(a, b, c, d); + double rgot = libtellurian_coarse_distance_radians(c, d, a, b); + double err = expect ? fabs(got / (R * expect) - 1.0) : got; + return err <= 1.0e-8 && got == rgot; +} + +int +main(void) +{ + ASSERT(check(0, 0, 0, 0, 0)); + ASSERT(check(0, 0, D90, 0, M_PI / 2.0)); + ASSERT(check(0, 0, 0, D90, M_PI / 2.0)); + ASSERT(check(0, 0, D180, 0, M_PI)); + ASSERT(check(0, 0, 0, D180, M_PI)); + ASSERT(check(0, 0, D45, 0, M_PI / 4.0)); + ASSERT(check(0, 0, 0, D45, M_PI / 4.0)); + ASSERT(check(-D90, 0, D90, 0, M_PI)); + ASSERT(check(0, -D90, 0, D90, M_PI)); + ASSERT(check(0, 0, D60, D90, M_PI / 2.0)); + ASSERT(check(0, 0, D30, D90, M_PI / 2.0)); + ASSERT(check(0, 0, D90, D90, M_PI / 2.0)); + ASSERT(check(0, 0, D45, D45, M_PI / 3.0)); + ASSERT(check(-D45, -D45, D45, D45, M_PI / 1.5)); + ASSERT(check(D45, -D45, D45, D45, M_PI / 3.0)); + ASSERT(check(-D45, D45, D45, D45, M_PI / 2.0)); + return 0; +} + + +#endif |