class LatLonToIsinGridMapper {

    static int computeN_v(double lat) {
        int N_v = (int) Math.ceil(Math.abs(Math.cos(Math.toRadians(lat))) * N_eq);
        /**
         * according to product spec:
         * "N_v is equal to cos(lat) * N_eq, rounded up to the nearest even integer"
         */
        if( N_v % 2 == 0 ) {
            return N_v;
        } else {
            return ++N_v;
        }
    }

    private  LatLonToIsinGridMapper();

}