Label in CheXpert dataset. #47

Hi, thank you for share your great work.
Could you please explain why the labels of 'Edema', 'Atelectasis' are replaced in this way?
if col in ['Edema', 'Atelectasis']:
self.df[col].replace(-1, 1, inplace=True)

As far as I know, in the chexpert labels, -1 represents negative, and 1 represent positive. I see that some diseases replace -1 with 0, but why the two diseases are different?

Thank you so much!