def get_ids(num_subjects=None, short=True):
    '\n        num_subjects   : number of subject IDs to get\n        short          : True of False, specifies whether to get short or long subject IDs\n\n    return:\n        subject_IDs    : list of subject IDs (length num_subjects)\n    '
    if short:
        subject_IDs = np.loadtxt(os.path.join(root_folder, 'subject_IDs.txt'), dtype=int)
        subject_IDs = subject_IDs.astype(str)
    else:
        subject_IDs = np.loadtxt(os.path.join(root_folder, 'full_IDs.txt'), dtype=str)
    if (num_subjects is not None):
        subject_IDs = subject_IDs[:num_subjects]
    return subject_IDs
num_subjects   : number of subject IDs to get
    short          : True of False, specifies whether to get short or long subject IDs

return:
    subject_IDs    : list of subject IDs (length num_subjects)
def get_ids(num_subjects=None, short=True):
    '\n        num_subjects   : number of subject IDs to get\n        short          : True of False, specifies whether to get short or long subject IDs\n\n    return:\n        subject_IDs    : list of subject IDs (length num_subjects)\n    '
    if short:
        subject_IDs = np.loadtxt(os.path.join(root_folder, 'subject_IDs.txt'), dtype=int)
        subject_IDs = subject_IDs.astype(str)
    else:
        subject_IDs = np.loadtxt(os.path.join(root_folder, 'full_IDs.txt'), dtype=str)
    if (num_subjects is not None):
        subject_IDs = subject_IDs[:num_subjects]
    return subject_IDs