In Lesson 9, annealers section, there is this function combine_scheds as defined below:

```
def combine_scheds(pcts, scheds):
assert sum(pcts) == 1.
pcts = tensor([0] + listify(pcts))
assert torch.all(pcts >= 0)
pcts = torch.cumsum(pcts, 0)
def _inner(pos):
idx = (pos >= pcts).nonzero().max()
if idx == 2: idx = 1
actual_pos = (pos-pcts[idx]) / (pcts[idx+1]-pcts[idx])
return scheds[idx](actual_pos)
return _inner
```

Can someone please explain the following part of this code?

idx = (pos >= pcts).nonzero().max()

if idx == 2: idx = 1

I cant understand the purpose of these 2 linesâ€¦ can someone please help me out?

Thanks in advance