Why is there a lr parameter in AffineGridGenFunction ?

[Cadene]

Hi,

Thanks for this awesome project!

I have a straightforward question. Why is there a lr parameter in AffineGridGenFunction?
https://github.com/Cadene/stn.pytorch/blob/master/script/functions/gridgen.py#L8

Also, is it useful to have a lr parameter in CylinderGridGenFunction?
https://github.com/Cadene/stn.pytorch/blob/master/script/functions/gridgen.py#L95

Thanks in advance :)