I’m trying to resume training and I am using torch.optim.lr_scheduler.MultiStepLR 35 for decreasing the learning rate. I noticed the constructor accepts a last_epoch parameter. So I tried to set it to the last epoch in which my checkpoint is made, and then simply resume training from that epoch forward.
When I tried to send a value for this parameter, I faced the error :

KeyError: “param ‘initial_lr’ is not specified in param_groups[0] when resuming an optimizer”

I have no idea what this means and how to get around it. The documentation is also vague to me and I really cant understand it. it talks about initial_lr, but there is no parameter named as such . I’m completely lost here!
Any help is greatly appreciated.
By the way, I’m using Pytorch 0.3.1