diffusers/pr_13966/en/api/schedulers/helios.md

HeliosScheduler

HeliosScheduler is based on the pyramidal flow-matching sampling introduced in Helios.

HeliosScheduler[[diffusers.HeliosScheduler]]

• model_output (torch.Tensor) -- The direct output from the learned diffusion model.
• timestep (int) -- The current discrete timestep in the diffusion chain.
• sample (torch.Tensor) -- A current instance of a sample created by the diffusion process.torch.TensorThe converted model output.

Convert the model output to the corresponding type the UniPC algorithm needs.

initialize the global timesteps and sigmas

Init the timesteps for each stage

• this_model_output (torch.Tensor) -- The model outputs at x_t.
• this_timestep (int) -- The current timestep t.
• last_sample (torch.Tensor) -- The generated sample before the last predictor x_{t-1}.
• this_sample (torch.Tensor) -- The generated sample after the last predictor x_{t}.
• order (int) -- The p of UniC-p at this step. The effective order of accuracy should be order + 1.torch.TensorThe corrected sample tensor at the current timestep.

One step for the UniC (B(h) version).

• model_output (torch.Tensor) -- The direct output from the learned diffusion model at the current timestep.
• prev_timestep (int) -- The previous discrete timestep in the diffusion chain.
• sample (torch.Tensor) -- A current instance of a sample created by the diffusion process.
• order (int) -- The order of UniP at this timestep (corresponds to the p in UniPC-p).torch.TensorThe sample tensor at the previous timestep.

One step for the UniP (B(h) version). Alternatively, self.solver_p is used if is specified.

• begin_index (int) -- The begin index for the scheduler.

Sets the begin index for the scheduler. This function should be run from pipeline before the inference.

Setting the timesteps and sigmas for each stage

• mu (float) -- The mu parameter for the time shift.
• sigma (float) -- The sigma parameter for the time shift.
• t (torch.Tensor) -- The input timesteps.torch.TensorThe time-shifted timesteps.

Apply time shifting to the sigmas.

scheduling_helios