Function UtmProjection.longitudeOfNaturalOrigin

Zone central meridian.

Longitude!T longitudeOfNaturalOrigin() const pure nothrow @nogc @property @safe;

Example

Example reading the longitude of natural origin. 

import geodesy;
const projection = UtmProjection!double.fromZone(
    wgs84!double(), UtmZone.fromNumber(33), UtmHemisphere.north);
assert(projection.longitudeOfNaturalOrigin.degrees == 15.0);