# 1D Sequence Classification

I am working with a long sequence (~60 000 timesteps) classification task with continuous input domain. The input has the shape (B, L, C) where B is the batch size, L is the sequence length (i.e. timesteps) and C is the number of features where each feature is continuous (i.e. values like 0.6, 0.2, 0.5, 1.3, etc.).

Since the sequence is very long, I can't directly apply an RNN or Transformer Encoder layer without exceeding memory limits. Some proposed methods use several CNN layers to "downsample" the sequence length before feeding it into an RNN model. A successful example of this includes the CNN-LSTM model. By introducing several subsequent Convolutional blocks followed by max-pooling it is possible to "downsample" the sequence length by a given factor. The sampled sequence would instead have a sequence length of 60 timesteps for instance, which is much more manageable for an LSTM model.

Does it make sense to directly substitute the LSTM model with a Transformer encoder? I have read that the transformer attention mechanism can complement the LSTM layers and be used in succession.

There also exist many variants of Transformers and other architectures designed for handling long sequences. Latest examples include Performer, Linformer, Reformer, Nyströmformer, BigBird, FNet, S4, CDIL-CNN. Does there exist a library similar to torchvision for implementing these models in pytorch without copy-pasting large amounts of code from the respective repositories?