2018

Hyperspherical Variational Auto-Encoders

Davidson, Tim R., Falorsi, Luca, De Cao, Nicola et al.

Understand

The Variational Auto-Encoder (VAE) is one of the most used unsupervised machine learning models.

  • But although the default choice of a Gaussian distribution for both the prior and posterior represents a mathematically convenient distribution often leading to competitive results, we show that this parameterization fails to model data with a latent hyperspherical structure.
  • To address this issue we propose using a von Mises-Fisher (vMF) distribution instead, leading to a hyperspherical latent space.
  • Through a series of experiments we show how such a hyperspherical VAE, or $\mathcal{S}$-VAE, is more suitable for capturing data with a hyperspherical latent structure, while outperforming a normal, $\mathcal{N}$-VAE, in low dimensions on other data types.

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