fix live preview & alternate uncond guidance for better quality

        tensor = denoiser_params.text_cond

        uncond = denoiser_params.text_uncond

        sigma_thresh = s_min_uncond

        if(torch.dot(sigma,sigma) < sigma.shape[0] * (sigma_thresh*sigma_thresh) and not is_edit_model):

        if self.step % 2 and s_min_uncond > 0 and not is_edit_model:

            # alternating uncond allows for higher thresholds without the quality loss normally expected from raising it

            sigma_threshold = s_min_uncond

            if(torch.dot(sigma,sigma) < sigma.shape[0] * (sigma_threshold*sigma_threshold) ):

                uncond = torch.zeros([0,0,uncond.shape[2]])

                x_in=x_in[:x_in.shape[0]//2]

                sigma_in=sigma_in[:sigma_in.shape[0]//2]

        devices.test_for_nans(x_out, "unet")

        if opts.live_preview_content == "Prompt":

            sd_samplers_common.store_latent(x_out[0:uncond.shape[0]])

            sd_samplers_common.store_latent(x_out[0:x_out.shape[0]-uncond.shape[0]])

        elif opts.live_preview_content == "Negative prompt":

            sd_samplers_common.store_latent(x_out[-uncond.shape[0]:])