def METHOD_NAME(ncdfdata): #{{{
    """
    inputs:
        ncdfdata is an opened netCDF4.Dataset
    outputs:
        position tuple
    """
    maxLevelCell = ncdfdata.variables['maxLevelCell'][:]
    npoints = np.sum(maxLevelCell)
    # point data
    lonCell = ncdfdata.variables['xCell'][:]
    latCell = ncdfdata.variables['yCell'][:]
    # note this is a coarse proxy for the cell center, but it should work for
    # this application
    vertLevel = ncdfdata.variables['refBottomDepth'][:]
    x = np.zeros((npoints))
    y = np.zeros((npoints))
    z = np.zeros((npoints))
    n = 0
    for aCell, nLevel in enumerate(maxLevelCell):
        # vertical grid
        x[n:(n+nLevel)] = lonCell[aCell]
        y[n:(n+nLevel)] = latCell[aCell]
        z[n:(n+nLevel)] = vertLevel[:nLevel]
        # counter
        n += nLevel
    return np.vstack((x,y,z)).T #}}}