def set_defaults(hotpotato):
    """
    Set default values for keys in a dictionary of input parameters.

    Parameters
    ----------
    hotpotato : dictionary
         Dictionary of input parameters gathered from a configuration script

    Returns
    -------
    hotpotato : dictionary
        Input dictionary with keys set to default values
    """
    # Default S/N threshold for ON pointings = 8
    if hotpotato['on_cutoff']=='':
        hotpotato['on_cutoff'] = 7.5
    # Default S/N threshold for OFF pointings = 6
    if hotpotato['off_cutoff']=='':
        hotpotato['off_cutoff'] = 6.0
    # Default cluster radius = 1 ms
    if hotpotato['cluster_radius']=='':
        hotpotato['cluster_radius'] = 1.0e-3
    return hotpotato