40 lines
1.5 KiB
Python
40 lines
1.5 KiB
Python
from ray.rllib.core.columns import Columns
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from ray.rllib.core.rl_module.torch.torch_rl_module import TorchRLModule
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from ray.rllib.utils.framework import try_import_torch
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torch, nn = try_import_torch()
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class DifferentiableTorchRLModule(TorchRLModule):
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"""Differentiable neural network to learn sinusoid curves.
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This `TorchRLModule`:
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- defines a simple neural network to learn sinusoid curves with two
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feed forward layern and ReLU activations,
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- defines a differentiable `forward` call by overriding the `_forward`
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method (which is implicitly used by the module's `forward` method); this
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enables `torch.func.functional_call?` to work.
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"""
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def setup(self):
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"""Sets up a simple neural network
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The network contains two hidden layers and ReLU activations. Note,
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input and output are single dimensional b/c the sinusoid curve is.
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"""
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self.net = nn.Sequential(
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nn.Linear(1, 40), nn.ReLU(), nn.Linear(40, 40), nn.ReLU(), nn.Linear(40, 1)
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)
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def _forward(self, batch, **kwargs):
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"""Defines method to be called for general forward path.
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Note, it is important that the `RLModule.forward` method contains the
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logic to be used for training forward pass b/c otherwise the functional
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call via `torch.func.functional_call` will not work. See for reference
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https://pytorch.org/docs/stable/generated/torch.func.functional_call.html.
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"""
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outs = {}
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outs["y_pred"] = self.net(batch[Columns.OBS])
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return outs
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