deeplearning/modulus/modulus-sym-v100/_modules/modulus/sym/models/dgm.html

Sym v1.0.0

Source code for modulus.sym.models.dgm

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# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
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#     http://www.apache.org/licenses/LICENSE-2.0
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# Unless required by applicable law or agreed to in writing, software
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from typing import List, Dict

import torch
import torch.nn as nn
from torch import Tensor


import modulus.sym.models.layers as layers
from modulus.sym.models.arch import Arch
from modulus.sym.key import Key


[docs]class DGMArch(Arch): """ A variation of the fully connected network. Reference: Sirignano, J. and Spiliopoulos, K., 2018. DGM: A deep learning algorithm for solving partial differential equations. Journal of computational physics, 375, pp.1339-1364. Parameters ---------- input_keys : List[Key] Input key list output_keys : List[Key] Output key list detach_keys : List[Key], optional List of keys to detach gradients, by default [] layer_size : int = 512 Layer size for every hidden layer of the model. nr_layers : int = 6 Number of hidden layers of the model. skip_connections : bool = False If true then apply skip connections every 2 hidden layers. activation_fn : layers.Activation = layers.Activation.SILU Activation function used by network. adaptive_activations : bool = False If True then use an adaptive activation function as described here https://arxiv.org/abs/1906.01170. weight_norm : bool = True Use weight norm on fully connected layers. """ def __init__( self, input_keys: List[Key], output_keys: List[Key], detach_keys: List[Key] = [], layer_size: int = 512, nr_layers: int = 6, activation_fn=layers.Activation.SIN, adaptive_activations: bool = False, weight_norm: bool = True, ) -> None: super().__init__( input_keys=input_keys, output_keys=output_keys, detach_keys=detach_keys ) in_features = sum(self.input_key_dict.values()) out_features = sum(self.output_key_dict.values()) if adaptive_activations: activation_par = nn.Parameter(torch.ones(1)) else: activation_par = None self.fc_start = layers.FCLayer( in_features=in_features, out_features=layer_size, activation_fn=activation_fn, weight_norm=weight_norm, ) self.dgm_layers = nn.ModuleList() for _ in range(nr_layers - 1): single_layer = {} for key in ["z", "g", "r", "h"]: single_layer[key] = layers.DGMLayer( in_features_1=in_features, in_features_2=layer_size, out_features=layer_size, activation_fn=activation_fn, weight_norm=weight_norm, activation_par=activation_par, ) self.dgm_layers.append(nn.ModuleDict(single_layer)) self.fc_end = layers.FCLayer( in_features=layer_size, out_features=out_features, activation_fn=layers.Activation.IDENTITY, weight_norm=False, activation_par=None, ) def _tensor_forward(self, x: Tensor) -> Tensor: x = self.process_input( x, self.input_scales_tensor, periodicity=self.periodicity, input_dict=self.input_key_dict, dim=-1, ) s = self.fc_start(x) for layer in self.dgm_layers: # TODO: this can be optimized, 'z', 'g', 'r' can be merged into a # single layer with 3x output size z = layer["z"](x, s) g = layer["g"](x, s) r = layer["r"](x, s) h = layer["h"](x, s * r) s = h - g * h + z * s x = self.fc_end(s) x = self.process_output(x, self.output_scales_tensor) return x
[docs] def forward(self, in_vars: Dict[str, Tensor]) -> Dict[str, Tensor]: x = self.concat_input( in_vars, self.input_key_dict.keys(), detach_dict=self.detach_key_dict, dim=-1, ) y = self._tensor_forward(x) return self.split_output(y, self.output_key_dict, dim=-1)

def _dict_forward(self, in_vars: Dict[str, Tensor]) -> Dict[str, Tensor]: """ This is the original forward function, left here for the correctness test. """ x = self.prepare_input( in_vars, self.input_key_dict.keys(), detach_dict=self.detach_key_dict, dim=-1, input_scales=self.input_scales, ) s = self.fc_start(x) for layer in self.dgm_layers: # TODO: this can be optimized, 'z', 'g', 'r' can be merged into a # single layer with 3x output size z = layer["z"](x, s) g = layer["g"](x, s) r = layer["r"](x, s) h = layer["h"](x, s * r) s = h - g * h + z * s x = self.fc_end(s) return self.prepare_output( x, self.output_key_dict, dim=-1, output_scales=self.output_scales )

© Copyright 2023, NVIDIA Modulus Team. Last updated on Aug 8, 2023.