To implement Contrastive Divergence (CD) for training a Restricted Boltzmann Machine (RBM), you perform a forward pass to compute probabilities, a Gibbs sampling step to reconstruct visible data, and calculate the weight updates based on the difference in statistics between the data and reconstruction. You can refer to the following code:
In the above code, we are using the following:
- Positive Phase: Compute statistics using the original data.
- Negative Phase: Use Gibbs sampling to generate reconstructions and compute statistics.
- Weight Update: Adjust weights and biases based on the difference between the two phases.
- Hyperparameters: kkk determines the number of Gibbs sampling steps. Commonly, k=1k=1k=1 (CD-1) is used for efficiency.
Hence by referring to the following you can implement contrastive divergence in training a restricted Boltzmann machine RBM for generative modeling