Found mistake in pytorch-lightning DQN example. How do I upload a fix?
I am learning deep RL, and as an exercise I looked through and tried to implement this example of DQN in pytorch lightning:
DQN example
I believe that I have found a bug and I am not sure how to flag it or how to upload a fix myself. This is my first time trying to contribute to an open source project and any advice will be greatly appreciated.
One line 106 of the section for the DQN Lightning Module, the expression for epsilon (which decays over the first eps_last_frame steps) is incorrect. The code is currently:
 epsilon = max( self.hparams.eps_end, self.hparams.eps_start - self.global_step + 1 / self.hparams.eps_last_frame, )
I believe this is incorrect for the following reason: 0 <= epsilon <= 1, so self.global_step immediately overcomes the other two terms. There is no decay, only a single timestep at eps_start + 1/eps_last_frame, and then timesteps at eps_end. This also seems like an error because with the default values,  eps_start + 1/eps_last_frame > 1.
The intended behavior is for the epsilon to decay linearly from eps_start to eps_end over the first eps_last_frame frames. I believe the second argument to max() should be:
self.hparams.eps_start - (self.global_step / self.hparams.eps_last_frame) * (self.hparams.eps_start - self.hparams.eps_end)
Who do I contact, or is there a way I can upload this fix myself?
Hello! This fix would be done in the Lightning Tutorials repo here: https://github.com/PyTorchLightning/lightning-tutorials

Fork the repo (button on top right)
Clone the repo from your fork
Go to the DQN example source code/notebook
Edit with your proposed fix
commit the changes and push them to your fork
Then go to the https://github.com/PyTorchLightning/lightning-tutorials/pulls and open a Pull Request.

Let me know if that helps and thanks for checking out the tutorials and the help!