optim.optimizer.state_dict.state not found when loading from checkpoint

[Chung-I]

I encountered an error when using Adam optimizer and resuming training from checkpoint, which states that state in Adam optimizer is not found. I found that the line optim.set_parameters(model.parameters()) wipe out states in
optim.optimizer.state_dict.state.

if not opt.train_from_state_dict and not opt.train_from:
        for p in model.parameters():
            p.data.uniform_(-opt.param_init, opt.param_init)
        encoder.load_pretrained_vectors(opt)
        decoder.load_pretrained_vectors(opt)
        optim = onmt.Optim(
            opt.optim, opt.learning_rate, opt.max_grad_norm,
            lr_decay=opt.learning_rate_decay,
            start_decay_at=opt.start_decay_at
        )
    else:
        print('Loading optimizer from checkpoint:')
        optim = checkpoint['optim']
        print(optim)

    optim.set_parameters(model.parameters())

after I move the line optim.set_parameters(model.parameters()) into the block under if statement, the code works fine:

if not opt.train_from_state_dict and not opt.train_from:
        for p in model.parameters():
            p.data.uniform_(-opt.param_init, opt.param_init)
        encoder.load_pretrained_vectors(opt)
        decoder.load_pretrained_vectors(opt)
        optim = onmt.Optim(
            opt.optim, opt.learning_rate, opt.max_grad_norm,
            lr_decay=opt.learning_rate_decay,
            start_decay_at=opt.start_decay_at
        )
        optim.set_parameters(model.parameters())
    else:
        print('Loading optimizer from checkpoint:')
        optim = checkpoint['optim']
        print(optim)

[ylhsieh]

Thanks for your very helpful tip!

[Chung-I]

@ylhsieh But I later found that the code above is just silencing the error rather than fixing it ...... Adam stop updating parameters when reading from a checkpoint.

[ylhsieh]

Thanks again! That is exactly what I was going to post just now. Wonder if anyone has a fix...

[srush]

(Superceded by more recent issue)