265 lines
8.2 KiB
Python
265 lines
8.2 KiB
Python
import torch
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from lightning import LightningModule
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from torch_geometric.data import Batch
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import importlib
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from matplotlib import pyplot as plt
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from matplotlib.tri import Triangulation
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from .model.finite_difference import FiniteDifferenceStep
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import os
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def import_class(class_path: str):
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module_path, class_name = class_path.rsplit(".", 1) # split last dot
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module = importlib.import_module(module_path) # import the module
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cls = getattr(module, class_name) # get the class
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return cls
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def _plot_mesh(pos_, y_, y_pred_, y_true_, batch, i, batch_idx):
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for j in [0, 10, 20, 30]:
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idx = (batch == j).nonzero(as_tuple=True)[0]
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y = y_[idx].detach().cpu()
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y_pred = y_pred_[idx].detach().cpu()
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pos = pos_[idx].detach().cpu()
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y_true = y_true_[idx].detach().cpu()
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y_true = torch.clamp(y_true, min=0)
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folder = f"{j:02d}_images"
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if os.path.exists(folder) is False:
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os.makedirs(folder)
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pos = pos.detach().cpu()
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tria = Triangulation(pos[:, 0], pos[:, 1])
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plt.figure(figsize=(24, 5))
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plt.subplot(1, 4, 1)
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plt.tricontourf(tria, y.squeeze().numpy(), levels=100)
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plt.colorbar()
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plt.title("Step t-1")
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plt.subplot(1, 4, 2)
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plt.tricontourf(tria, y_pred.squeeze().numpy(), levels=100)
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plt.colorbar()
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plt.title("Step t Predicted")
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plt.subplot(1, 4, 3)
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plt.tricontourf(tria, y_true.squeeze().numpy(), levels=100)
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plt.colorbar()
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plt.title("t True")
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plt.subplot(1, 4, 4)
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plt.tricontourf(tria, (y_true - y_pred).squeeze().numpy(), levels=100)
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plt.colorbar()
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plt.title("Error")
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plt.suptitle("GNO", fontsize=16)
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name = f"{folder}/{j:04d}_graph_iter_{i:04d}.png"
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plt.savefig(name, dpi=72)
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plt.close()
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def _plot_losses(losses, batch_idx):
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folder = f"{batch_idx:02d}_images"
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plt.figure()
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plt.plot(losses)
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plt.yscale("log")
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plt.xlabel("Iteration")
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plt.ylabel("Loss")
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plt.title("Test Loss over Iterations")
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plt.grid(True)
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file_name = f"{folder}/test_loss.png"
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plt.savefig(file_name, dpi=300)
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plt.close()
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class GraphSolver(LightningModule):
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def __init__(
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self,
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model_class_path: str,
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model_init_args: dict = {},
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loss: torch.nn.Module = None,
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unrolling_steps: int = 1,
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):
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super().__init__()
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self.model = import_class(model_class_path)(**model_init_args)
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# for param in self.model.parameters():
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# print(f"Param: {param.shape}, Grad: {param.grad}")
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# print(f"Param: {param[0]}")
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self.loss = loss if loss is not None else torch.nn.MSELoss()
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self.unrolling_steps = unrolling_steps
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def _compute_loss(self, x, y):
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return self.loss(x, y)
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def _log_loss(self, loss, batch, stage: str):
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self.log(
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f"{stage}/loss",
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loss,
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on_step=False,
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on_epoch=True,
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prog_bar=True,
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batch_size=int(batch.num_graphs),
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)
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return loss
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@staticmethod
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def _compute_c_ij(c, edge_index):
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"""
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TODO: add docstring.
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"""
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return (0.5 * (c[edge_index[0]] + c[edge_index[1]])).squeeze()
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def _compute_model_steps(
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self,
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x,
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edge_index,
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edge_attr,
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boundary_mask,
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boundary_values,
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conductivity,
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):
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out = self.model(x, edge_index, edge_attr, conductivity)
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out[boundary_mask] = boundary_values.unsqueeze(-1)
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return out
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def _preprocess_batch(self, batch: Batch):
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x, y, c, edge_index, edge_attr = (
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batch.x,
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batch.y,
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batch.c,
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batch.edge_index,
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batch.edge_attr,
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)
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edge_attr = 1 / edge_attr
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conductivity = self._compute_c_ij(c, edge_index)
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edge_attr = edge_attr * conductivity
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return x, y, edge_index, edge_attr, conductivity
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def training_step(self, batch: Batch):
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x, y, edge_index, edge_attr, conductivity = self._preprocess_batch(
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batch
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)
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losses = []
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for i in range(self.unrolling_steps):
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out = self._compute_model_steps(
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x,
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edge_index,
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edge_attr,
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# deg,
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batch.boundary_mask,
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batch.boundary_values,
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conductivity,
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)
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x = out
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losses.append(self.loss(out.flatten(), y[:, i, :].flatten()))
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loss = torch.stack(losses).mean()
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self._log_loss(loss, batch, "train")
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for i, layer in enumerate(self.model.layers):
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self.log(
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f"alpha_{i}",
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layer.alpha,
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prog_bar=True,
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on_epoch=True,
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on_step=False,
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batch_size=int(batch.num_graphs),
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)
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self.log(
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"dt",
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self.model.dt,
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prog_bar=True,
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on_epoch=True,
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on_step=False,
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batch_size=int(batch.num_graphs),
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)
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return loss
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def validation_step(self, batch: Batch, batch_idx):
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x, y, edge_index, edge_attr, conductivity = self._preprocess_batch(
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batch
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)
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# deg = self._compute_deg(edge_index, edge_attr, x.size(0))
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losses = []
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pos = batch.pos
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for i in range(self.unrolling_steps):
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out = self._compute_model_steps(
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# torch.cat([x,pos], dim=-1),
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x,
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edge_index,
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edge_attr,
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# deg,
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batch.boundary_mask,
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batch.boundary_values,
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conductivity,
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)
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if (
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batch_idx == 0
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and self.current_epoch % 10 == 0
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and self.current_epoch > 0
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):
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_plot_mesh(
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batch.pos,
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x,
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out,
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y[:, i, :],
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batch.batch,
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i,
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self.current_epoch,
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)
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x = out
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losses.append(self.loss(out, y[:, i, :]))
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loss = torch.stack(losses).mean()
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self._log_loss(loss, batch, "val")
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return loss
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def _check_convergence(self, y_pred, y_true, tol=1e-3):
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l2_norm = torch.norm(y_pred - y_true, p=2)
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y_true_norm = torch.norm(y_true, p=2)
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rel_error = l2_norm / (y_true_norm + 1e-8)
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return rel_error.item() < tol
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def test_step(self, batch: Batch, batch_idx):
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x, y, edge_index, edge_attr, conductivity = self._preprocess_batch(
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batch
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)
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# deg = self._compute_deg(edge_index, edge_attr, x.size(0))
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losses = []
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all_losses = []
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norms = []
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for i in range(self.unrolling_steps):
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out = self._compute_model_steps(
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# torch.cat([x,pos], dim=-1),
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x,
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edge_index,
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edge_attr,
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# deg,
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batch.boundary_mask,
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batch.boundary_values,
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conductivity,
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)
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norms.append(torch.norm(out - x, p=2).item())
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x = out
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loss = self.loss(out, y[:, i, :])
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all_losses.append(loss.item())
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losses.append(loss)
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# if (
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# batch_idx == 0
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# and self.current_epoch % 10 == 0
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# and self.current_epoch > 0
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# ):
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# _plot_mesh(
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# batch.pos,
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# x,
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# out,
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# y[:, i, :],
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# batch.batch,
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# i,
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# self.current_epoch,
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# )
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loss = torch.stack(losses).mean()
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# if (
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# batch_idx == 0
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# and self.current_epoch % 10 == 0
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# and self.current_epoch > 0
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# ):
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_plot_losses(norms, self.current_epoch)
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self._log_loss(loss, batch, "test")
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return loss
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def configure_optimizers(self):
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optimizer = torch.optim.AdamW(self.parameters(), lr=1e-3)
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return optimizer
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