How to derive the equation of alpha_cosine_log_snr

[winnechan]

Thanks for your excellent project! I am still confused about how to derive the equation of alpha_cosine_log_snr after reading IDDPM and VDM, can somebody help?

denoising-diffusion-pytorch/denoising_diffusion_pytorch/continuous_time_gaussian_diffusion.py

Line 69 in dfbafee

def alpha_cosine_log_snr(t, s = 0.008):

[lucidrains]

i was also stuck on this for like a week, as there were no easy answers to look up online. i finally sat down one morning and derived it by hand on the back of an envelope