Files
thermal-conduction-ml/ThermalSolver/model/learnable_finite_difference.py

127 lines
3.8 KiB
Python

import torch
import torch.nn as nn
from torch_geometric.nn import MessagePassing
from torch.nn.utils import spectral_norm
from matplotlib.tri import Triangulation
from matplotlib import pyplot as plt
def _plot_mesh(y_pred, batch, iteration=None):
idx = batch.batch == 0
y = batch.y[idx].detach().cpu()
y_pred = y_pred[idx].detach().cpu()
pos = batch.pos[idx].detach().cpu()
pos = pos.detach().cpu()
tria = Triangulation(pos[:, 0], pos[:, 1])
plt.figure(figsize=(18, 5))
plt.subplot(1, 3, 1)
plt.tricontourf(tria, y.squeeze().numpy(), levels=14)
plt.colorbar()
plt.title("True temperature")
plt.subplot(1, 3, 2)
plt.tricontourf(tria, y_pred.squeeze().numpy(), levels=14)
plt.colorbar()
plt.title("Predicted temperature")
plt.subplot(1, 3, 3)
plt.tricontourf(tria, torch.abs(y_pred - y).squeeze().numpy(), levels=14)
plt.colorbar()
plt.title("Error")
plt.suptitle("GNO", fontsize=16)
name = (
f"images/gno_iter_{iteration:04d}.png"
if iteration is not None
else "gno.png"
)
plt.savefig(name, dpi=72)
plt.close()
class FiniteDifferenceStep(MessagePassing):
"""
TODO: add docstring.
"""
def __init__(self, edge_ch=5, hidden_dim=16, aggr: str = "add"):
super().__init__(aggr=aggr)
self.x_embedding = nn.Sequential(
spectral_norm(nn.Linear(1, hidden_dim // 2)),
nn.GELU(),
spectral_norm(nn.Linear(hidden_dim // 2, hidden_dim)),
)
self.edge_embedding = nn.Sequential(
spectral_norm(nn.Linear(edge_ch, hidden_dim // 2)),
nn.GELU(),
spectral_norm(nn.Linear(hidden_dim // 2, hidden_dim)),
)
self.update_net = nn.Sequential(
spectral_norm(nn.Linear(2 * hidden_dim, hidden_dim)),
nn.GELU(),
spectral_norm(nn.Linear(hidden_dim, hidden_dim)),
nn.GELU(),
# spectral_norm(nn.Linear(hidden_dim // 2, 1)),
)
# self.message_net = nn.Sequential(
# spectral_norm(nn.Linear(2 * hidden_dim, hidden_dim)),
# nn.GELU(),
# spectral_norm(nn.Linear(hidden_dim, hidden_dim // 2)),
# nn.GELU(),
# spectral_norm(nn.Linear(hidden_dim // 2, hidden_dim)),
# )
self.out_net = nn.Sequential(
spectral_norm(nn.Linear(hidden_dim, hidden_dim // 2)),
nn.GELU(),
spectral_norm(nn.Linear(hidden_dim // 2, 1)),
)
def forward(self, x, edge_index, edge_attr, deg):
"""
TODO: add docstring.
"""
x_ = self.x_embedding(x)
edge_attr_ = self.edge_embedding(edge_attr)
out = self.propagate(edge_index, x=x_, edge_attr=edge_attr_, deg=deg)
return self.out_net(x_ + out)
def message(self, x_j, edge_attr):
"""
TODO: add docstring.
"""
# msg_input = torch.cat([x_j, edge_attr], dim=-1)
# return self.message_net(msg_input) * edge_attr[:, 3].view(-1, 1)
return x_j * edge_attr
def update(self, aggr_out, x):
"""
TODO: add docstring.
"""
update_input = torch.cat([x, aggr_out], dim=-1)
return self.update_net(update_input)
# return self.update_net(aggr_out)
# return aggr_out
# h = self.update_net(aggr_out, x)
# return h
def aggregate(self, inputs, index, deg):
"""
TODO: add docstring.
"""
out = super().aggregate(inputs, index)
deg = deg + 1e-7
return out / deg.view(-1, 1)
# # Da fare:
# # - Finire calcolo della loss su ogni step e poi media
# # - Test con vari modelli
# # - Se non dovesse funzionare, provare ad adeguare il criterio di uscita
# # PINN batching:
# # - Provare singola condizione
# # - Ottimizzatore del secondo ordine (LBFGS)