---
title: sequence_descriptor
framework: accelerate
role: symbol
role_heading: Instance Property
path: accelerate/bnnslayerparameterslstm/sequence_descriptor
---

# sequence_descriptor

A 1D array of unsigned-integer elements that determines the batch size for each step.

## Declaration

```swift
var sequence_descriptor: BNNSNDArrayDescriptor
```

## Discussion

Discussion If seq_len is greater than 1 and the data property of this descriptor is nil, BNNS uses the same batch_size for the entire sequence.

## See Also

### Instance Properties

- [input_size](accelerate/bnnslayerparameterslstm/input_size.md)
- [hidden_size](accelerate/bnnslayerparameterslstm/hidden_size.md)
- [batch_size](accelerate/bnnslayerparameterslstm/batch_size.md)
- [num_layers](accelerate/bnnslayerparameterslstm/num_layers.md)
- [seq_len](accelerate/bnnslayerparameterslstm/seq_len.md)
- [dropout](accelerate/bnnslayerparameterslstm/dropout.md)
- [lstm_flags](accelerate/bnnslayerparameterslstm/lstm_flags.md)
- [input_descriptor](accelerate/bnnslayerparameterslstm/input_descriptor.md)
- [output_descriptor](accelerate/bnnslayerparameterslstm/output_descriptor.md)
- [input_gate](accelerate/bnnslayerparameterslstm/input_gate.md)
- [forget_gate](accelerate/bnnslayerparameterslstm/forget_gate.md)
- [candidate_gate](accelerate/bnnslayerparameterslstm/candidate_gate.md)
- [output_gate](accelerate/bnnslayerparameterslstm/output_gate.md)
- [hidden_activation](accelerate/bnnslayerparameterslstm/hidden_activation.md)