def get_function_handle(method, var):
    """
    Return a function handle to a given calculation method.

    Parameters
    ----------
    method : str
        Identifier of the calculation method to return a handle to.
    var : dict
        Local variables needed in the threshold method.

    Returns
    -------
    f_handle : function
        Handle to calculation `method` defined in this globals scope.

    """

    return globals()['wrap_calculate_using_' + method](var)