docstr: Sequence decoding and threshold estimation used for inference. 
docstr_tok: ["Sequence","decoding","and","threshold","estimation","used","for","inference","."]
code: def decode_seq(self, x: np.ndarray) -> Tuple[np.ndarray, np.ndarray]:
      """Sequence decoding and threshold estimation used for inference."""
      seq_len = np.shape(x)[1]
      n_batch = x.shape[0]
  
      # use encoder to get state vectors
      init_state = self.encoder(x)[1]
  
      # generate start of target sequence
      decoder_input = np.reshape(x[:, 0, :], (n_batch, 1, -1))
  
      # initialize hidden states used to compute outlier thresholds
      z = np.zeros(
          (n_batch, seq_len, init_state[0].numpy().shape[1])
      ).astype(np.float32)
  
      # sequential prediction of time series
      decoded_seq = np.zeros_like(x)
      decoded_seq[:, 0, :] = x[:, 0, :]
      i = 1
      while i < seq_len:
          # decode step in sequence
          decoder_output = self.decoder(
              decoder_input, init_state=init_state
          )
          decoded_seq[:, i : i + 1, :] = decoder_output[0].numpy()
          init_state = decoder_output[2]
  
          # update hidden state decoder used for outlier threshold
          z[:, i : i + 1, :] = decoder_output[1].numpy()
  
          # update next decoder input
          decoder_input = np.zeros_like(decoder_input)
          decoder_input[:, :1, :] = decoder_output[0].numpy()
  
          i += 1
  
      # compute outlier thresholds
      z = self.threshold_net(z)
      threshold_est = self.threshold_est(z).numpy()
  
      return decoded_seq, threshold_est
  
imports: import numpy
  import tensorflow
  from tensorflow.keras.layers import Bidirectional, Concatenate, Dense, Flatten, Layer, LSTM
  from typing import Callable, List, Tuple
  from alibi_detect.utils.tensorflow.distance import relative_euclidean_distance
label_desc: Use image node_id 3 for calling the Seq2Seq obj's underlying member method code with example usage: obj.decode_seq(x) and returns: decoded_seq,  threshold_est