Implementation error of v_prediction in eulara and eular

I came across a potential inconsistency in the implementation of v_prediction within the Euler scheduler when examining the source code. Specifically, in the computation of pred_original_sample, the formula is given as:
`pred_original_sample = model_output * (-sigma / (sigma**2 + 1) ** 0.5) + (sample / (sigma**2 + 1))`
Where sigma is calculated as:
`sigmas = np.array(((1 - self.alphas_cumprod) / self.alphas_cumprod) ** 0.5)`
Substituting the definition of sigma into the equation for pred_original_sample, we arrive at:
`pred_original_sample = sample * alphas_cumprod - model_output * ((1-alphas_cumprod) ** 0.5)`
Here, it appears that `sample * alphas_cumprod` is missing a square root operation on `alphas_cumprod`. Shouldn't this be `sample * (alphas_cumprod**0.5)`? This seems to be an inconsistency, especially considering that in the DDIM scheduler as in
`(alpha_prod_t**0.5) * sample - (beta_prod_t**0.5) * model_output`.
Could this be an error?

Localiser l’implémentation du scheduler Euler et le calcul de pred_original_sample. Vérifier la substitution signalée pour sigma par rapport à l’expression DDIM et à la convention de prédiction du scheduler. La tâche est terminée lorsqu’il a été déterminé si la racine carrée manque, et que l’implémentation a été documentée ou corrigée en conséquence.

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