vak.nn.loss.umap.convert_distance_to_probability

vak.nn.loss.umap.convert_distance_to_probability(distances, a=1.0, b=1.0)

Convert distances to probability.

Computes equation (2.6) of Sainburg McInnes Gentner 2021, \(q_{ij} = (1 + a bs{z_i - z_j}^{2b} )^{-1}\).

The function uses torch.log1p to avoid floating point error: -torch.log1p(a * distances ** (2 * b)). See https://en.wikipedia.org/wiki/Natural_logarithm#lnp1