An implementation of the sampling algorithms in Elucidating the Design Space of Diffusion-Based Generative Models [Karras et al., 2022].

• Algorithm 1. Deterministic sampling. With two versions:
  • Heun's 2nd order method.
  • Euler's (1st order) method (aka Heun's without steps 6-8).
• Algorithm 2. Stochastic sampling.
  • A modified Euler-Maruyama method.

(the algorithm version for the iDDPM case is not yet implemented).