Questions about learning rate decay

[Jiaolong]

In the paper section 4.1, it is said:
ηp = η0(1 + αp)−β, where p is the training progress changing from 0 to 1

I understand p = iter_num/max_iters

However, in the following pytorch code:

CDAN/pytorch/lr_schedule.py

Line 3 in f788906

lr = lr * (1 + gamma * iter_num) ** (-power)

and also in the tensorflow code:
https://github.com/thuml/CDAN/blob/master/tensorflow/train.py#L13

p = iter_num is used instead of p = iter_num/max_iters

Can you explain about this? Thanks!