This bug causes the following error in matlab:
Reference to non-existent filed: Dname.v3d_time
if (S.def_zeta),
Dname.zeta_time = 'zeta_time'; Dsize.zeta_time = S.zeta_time;
end
if (S.def_v2d),
Dname.v2d_time = 'v2d_time'; Dsize.v2d_time = S.v2d_time;
end
if (S.def_v3d),
Dname.v2d_time = 'v3d_time'; Dsize.v3d_time = S.v3d_time;
end