dify the
polynomial fitting formula in log-rho space instead of the original linear t space in DEIS paper. The modification
enjoys closed-form coefficients for exponential multistep update instead of replying on the numerical solver. More
variants of DEIS can be found in https://github.com/qsh-zh/deis.
Currently, we support the log-rho multistep DEIS. We recommend to use solver_order=2 / 3 while solver_order=1
reduces to DDIM.
We also support t