@Test
public void testComputeB_v() throws Exception {

    final double cellSizeY = 180.0 / 2004.0;
    assertEquals(0, LatLonToIsinGridMapper.computeB_v(cellSizeY * 1002));
    assertEquals(2, LatLonToIsinGridMapper.computeB_v(cellSizeY * 1001));
    assertEquals(10, LatLonToIsinGridMapper.computeB_v(cellSizeY * 1000));
    assertEquals(24, LatLonToIsinGridMapper.computeB_v(cellSizeY * 999));
    final int equatorB_v = LatLonToIsinGridMapper.computeB_v(cellSizeY * 0);
    assertEquals(2 * equatorB_v + LatLonToIsinGridMapper.N_eq - 2,
                 LatLonToIsinGridMapper.computeB_v(cellSizeY * -1002));
}