Attempting multiplication of list and float.

[ghost]

In the function below we save hill_model['data']['y'] as a list of floats.

def train_hill_model(df, mc_df, adstock_params, media, sm):
    data, sc = create_hill_model_data(df, mc_df, adstock_params, media)
    fit = sm.sampling(data=data, iter=2000, chains=4)
    fit_result = fit.extract()
    hill_model = {
        'beta_hill_list': fit_result['beta_hill'].tolist(),
        'ec_list': fit_result['ec'].tolist(),
        'slope_list': fit_result['slope'].tolist(),
        'sc': sc,
        'data': {
            'X': data['X'].tolist(),
            'y': data['y'].tolist(),
        }
    }
    return hill_model

However later on we try to multiply hill_model['data']['y'] by a float. Since it is a list it can't legally be multiplied by a float, and multiplication by an integer just increases the size of the list.

def evaluate_hill_model(hill_model, hill_model_params):
    x = hill_model['data']['X']
    y_true = hill_model['data']['y'] * hill_model['sc']['y']
    print(y_true)
    y_pred = hill_model_predict(hill_model_params, x) * hill_model['sc']['y']
    print(y_pred)
    print('mape on original data: ', 
         mean_absolute_percentage_error(y_true, y_pred))
    return y_true, y_pred

To be able to preform the multiplication hill_model['data']['y'] * hill_model['sc']['y'] then hill_model['data']['y'] needs to be a numpy array, not a list.

[ghost]

The simple solution is to just remove the .tolist() method from data['X'] and data['y]

def train_hill_model(df, mc_df, adstock_params, media, sm):
    data, sc = create_hill_model_data(df, mc_df, adstock_params, media)
    fit = sm.sampling(data=data, iter=2000, chains=4)
    fit_result = fit.extract()
    hill_model = {
        'beta_hill_list': fit_result['beta_hill'].tolist(),
        'ec_list': fit_result['ec'].tolist(),
        'slope_list': fit_result['slope'].tolist(),
        'sc': sc,
        'data': {
            'X': data['X'],
            'y': data['y'],
        }
    }
    return hill_model

[sibylhe]

Thanks for pointing out this! Your solution is correct.
tolist() is used to save the model as json file, because arrays cannot be saved as json. I will revise those model saving and loading functions later this weekend.

[ghost]

No problem! Thanks for putting this together; I've found it quite helpful.

[sibylhe]

For the sake of model storage, I still prefer to store data['X'] and data['y'] as lists, so that the hill model can be saved as json using save_json(). I modified evaluate_hill_model(), converting them to arrays.