Relative Root Mean Squared Error (RRMSE)

RRMSE.py

def relative_root_mean_squared_error(true, pred):
    n = len(true) # update
    num = np.sum(np.square(true - pred)) / n  # update
    den = np.sum(np.square(pred))
    squared_error = num/den
    rrmse_loss = np.sqrt(squared_error)
    return rrmse_loss

it seems this formula has an error.
need to divide with the average but it divides with the root average. because the average value is inside of the root.

This formula seems to be wrong
It should be like rmse/np.mean(true)