Why do this calculation in the code?

[THtanghuan]

Hi,thank you for this code. I want to know why do this calculation in the code?

become original temperature

temper_predict = np.array(test_predict)(temper_max - temper_min) + temper_min
temper_truth = np.array(temper_truth)(temper_max - temper_min) + temper_min

Thank you.