def default_params(model, update_dict=None):
    """
    Loads and updates default model parameters

    Parameters
    ----------

    model : str
        The name of a model

    update_dict : dict
        A dict to update default parameters

    Returns
    ----------

    params : dict
        A dictionary of parameters
    """

    if model in parameters:
        params = parameters[model].copy()
    else:
        params = None

    if update_dict:
        if params is None:
            params = {}
        params.update(update_dict)

    return params

    Loads and updates default model parameters

    Parameters
    ----------

    model : str
        The name of a model

    update_dict : dict
        A dict to update default parameters

    Returns
    ----------

    params : dict
        A dictionary of parameters
    
hypertools/_shared/params.py