import json


def read_config(config_file):
    """ Read parameters from config file.
    
    Keyword arguments:
    config_file -- json file containing input parameters

    Return:
    coef -- dictionary containing coefficients
    input_conf -- dictionary containing input parameters
    output_conf -- dictionary containing output parameters

    """
    
    with open(config_file, "r") as jsonfile:
        data = json.load(jsonfile)
 
    coef = data['coef']
    input_conf = data['input']
    output_conf = data['output']
    
    return coef, input_conf, output_conf