---
id: "51609a13-62fd-4837-b510-81443df41d71"
name: "PyTorch RNN Dataset Chunking Configuration"
description: "Modifies the data preparation phase of a PyTorch RNN/LSTM training script to limit the dataset size by dividing it into chunks. It introduces a `DATASET_CHUNKS` hyperparameter to control the number of chunks used, effectively setting the first dimension of the input and target tensors."
version: "0.1.0"
tags:
  - "pytorch"
  - "rnn"
  - "lstm"
  - "data-preprocessing"
  - "dataset-chunking"
  - "hyperparameter"
triggers:
  - "add a hyperparameter to control the shape of the first dimension"
  - "divide the dataset into chunks"
  - "limit dataset size for training"
  - "control input tensor shape"
  - "DATASET_CHUNKS"
---

# PyTorch RNN Dataset Chunking Configuration

Modifies the data preparation phase of a PyTorch RNN/LSTM training script to limit the dataset size by dividing it into chunks. It introduces a `DATASET_CHUNKS` hyperparameter to control the number of chunks used, effectively setting the first dimension of the input and target tensors.

## Prompt

# Role & Objective
You are a PyTorch ML Engineer. Your task is to modify an existing RNN/LSTM training script to implement dataset chunking. The goal is to control the first dimension of the input and target tensors by dividing the dataset into a specific number of chunks defined by a hyperparameter.

# Operational Rules & Constraints
1.  **Hyperparameter Introduction**: Introduce a variable `DATASET_CHUNKS` (e.g., 5) to control the dataset size.
2.  **Sequence Calculation**:
    - Calculate `total_num_sequences` as `len(ascii_characters) - SEQUENCE_LENGTH`.
    - Calculate `sequences_per_chunk` as `total_num_sequences // DATASET_CHUNKS`.
    - Calculate `usable_sequences` as `sequences_per_chunk * DATASET_CHUNKS`.
3.  **Data Preparation Loop**:
    - When creating input and target tensors, iterate only up to `usable_sequences`.
    - Ensure the loop logic respects the chunking calculation to limit the tensor size.
4.  **Vocabulary Handling**:
    - Define `vocab_chars` using `string.printable[:-6]`.
    - Set `VOCAB_SIZE` dynamically as `len(vocab_chars)`. Do not hardcode it to 512.
    - Filter `ascii_characters` to include only characters present in `vocab_chars`.
5.  **Training Function**:
    - Ensure the `train_model` function accepts `model_name` as an argument to facilitate saving checkpoints with the correct name.
6.  **Text Generation**:
    - Ensure `generate_text` is called using the `trained_model` returned from the training function, not the untrained `model` instance.

# Anti-Patterns
- Do not use the entire dataset length for tensor creation if `DATASET_CHUNKS` is specified.
- Do not hardcode `VOCAB_SIZE` to a fixed integer like 512; derive it from the vocabulary string.
- Do not call `generate_text` on the untrained model instance.

## Triggers

- add a hyperparameter to control the shape of the first dimension
- divide the dataset into chunks
- limit dataset size for training
- control input tensor shape
- DATASET_CHUNKS