class FuturePrediction(torch.nn.Module): def __init__(self, in_channels, latent_dim, n_gru_blocks=3, n_res_layers=3): super().__init__() self.n_gru_blocks = n_gru_blocks # Convolutional recurrent model with z_t as an initial hidden state and inputs the sample # from the probabilistic model. The architecture of the model is: # [Spatial GRU - [Bottleneck] x n_res_layers] x n_gru_blocks self.spatial_grus = [] self.res_blocks = [] for i in range(self.n_gru_blocks): gru_in_channels = latent_dim if i == 0 else in_channels self.spatial_grus.append(SpatialGRU(gru_in_channels, in_channels)) self.res_blocks.append(torch.nn.Sequential(*[Bottleneck(in_channels) for _ in range(n_res_layers)])) self.spatial_grus = torch.nn.ModuleList(self.spatial_grus) self.res_blocks = torch.nn.ModuleList(self.res_blocks) def forward(self, x, hidden_state): # x has shape (b, n_future, c, h, w), hidden_state (b, c, h, w) for i in range(self.n_gru_blocks): x = self.spatial_grus[i](x, hidden_state, flow=None) b, n_future, c, h, w = x.shape x = self.res_blocks[i](x.view(b * n_future, c, h, w)) x = x.view(b, n_future, c, h, w) return x是什么意思？

这是一个基于卷积循环神经网络的模型，用于进行未来预测。该模型包括若干个 SpatialGRU 模块和若干个 Bottleneck 模块，可以接受输入 x 和初始隐藏状态 hidden_state，输出预测结果 x。其中，x 的形状为 (b, n_future, c, h, w)，表示批次大小为 b，未来预测数为 n_future，通道数为 c，高度为 h，宽度为 w；hidden_state 的形状为 (b, c, h, w)，表示批次大小为 b，通道数为 c，高度为 h，宽度为 w。在 forward 方法中，会循环执行若干次 SpatialGRU 和 Bottleneck 模块，最终输出预测结果 x。