`warmup_lr` is computed incorrectly in `step_ReduceLROnPlateau`

[LvJC]

I wonder whether you forgot to modify like the line shown below in:

pytorch-gradual-warmup-lr/warmup_scheduler/scheduler.py

Line 44 in 6b5e895

warmup_lr = [base_lr * ((self.multiplier - 1.) * self.last_epoch / self.total_epoch + 1.) for base_lr in self.base_lrs]

+ warmup_lr = self.get_lr()
- warmup_lr = [base_lr * ((self.multiplier - 1.) * self.last_epoch / self.total_epoch + 1.) for base_lr in self.base_lrs]

---

Here is the details:

1. When I use ReduceLROnPlateau as the after_scheduler of GradualWarmupScheduler, the warm-up failed. The way I get the learning rate is: optim.param_groups[0]['lr']. Then I use get_lr to get the learning rate, I found it is correct.
2. I use StepLR as the after_scheduler, I found there was no exception and no error.

Therefor, I think the learning rate of the optimizer hadn't been warmed up correctly.

[jonashaag]

#18

[BCWang93]

Hi,how do you use ReduceLROnPlateau as the after_scheduler,when I use this as after_scheduler,the warm up in the first epoch is not change.

[LvJC]

Hi,how do you use ReduceLROnPlateau as the after_scheduler,when I use this as after_scheduler,the warm up in the first epoch is not change.

https://github.com/LvJC/pytorch-gradual-warmup-lr

[BCWang93]

Hi,how do you use ReduceLROnPlateau as the after_scheduler,when I use this as after_scheduler,the warm up in the first epoch is not change.

https://github.com/LvJC/pytorch-gradual-warmup-lr

Hi,I had replace this line

• warmup_lr = self.get_lr()

• warmup_lr = [base_lr * ((self.multiplier - 1.) * self.last_epoch / self.total_epoch + 1.) for base_lr in self.base_lrs]
  I use the warm_up lr is 5e-5 and 1epoch, and the after_scheduler init lr is 5e-4.But When I running,I find the first epoch lr is also 5e-4,so,I think there have other error?Thanks!

[LvJC]

Hi,how do you use ReduceLROnPlateau as the after_scheduler,when I use this as after_scheduler,the warm up in the first epoch is not change.

https://github.com/LvJC/pytorch-gradual-warmup-lr

Hi,I had replace this line

• warmup_lr = self.get_lr()

• warmup_lr = [base_lr * ((self.multiplier - 1.) * self.last_epoch / self.total_epoch + 1.) for base_lr in self.base_lrs]
  I use the warm_up lr is 5e-5 and 1epoch, and the after_scheduler init lr is 5e-4.But When I running,I find the first epoch lr is also 5e-4,so,I think there have other error?Thanks!

You can re-refer it, I updated it just now. I think the main cause is the get_last_lr function.

[BCWang93]

Hi,how do you use ReduceLROnPlateau as the after_scheduler,when I use this as after_scheduler,the warm up in the first epoch is not change.

https://github.com/LvJC/pytorch-gradual-warmup-lr

Hi,I had replace this line

• warmup_lr = self.get_lr()
• warmup_lr = [base_lr * ((self.multiplier - 1.) * self.last_epoch / self.total_epoch + 1.) for base_lr in self.base_lrs]
  I use the warm_up lr is 5e-5 and 1epoch, and the after_scheduler init lr is 5e-4.But When I running,I find the first epoch lr is also 5e-4,so,I think there have other error?Thanks!

You can re-refer it, I updated it just now. I think the main cause is the get_last_lr function.

Thanks!I will test it.

[BCWang93]

Hi,how do you use ReduceLROnPlateau as the after_scheduler,when I use this as after_scheduler,the warm up in the first epoch is not change.

https://github.com/LvJC/pytorch-gradual-warmup-lr

Hi,I had replace this line

• warmup_lr = self.get_lr()
• warmup_lr = [base_lr * ((self.multiplier - 1.) * self.last_epoch / self.total_epoch + 1.) for base_lr in self.base_lrs]
  I use the warm_up lr is 5e-5 and 1epoch, and the after_scheduler init lr is 5e-4.But When I running,I find the first epoch lr is also 5e-4,so,I think there have other error?Thanks!

You can re-refer it, I updated it just now. I think the main cause is the get_last_lr function.

Hi,I test this methods,but this has same problem,the first epochs lr is also 5e-4.But,when I change the after_scheduler to cosin_scheduler,the running is right.

[IamSVP94]

Hi there! Still do not work with ReduceLROnPlateau