import numpy as np import torch from typing import Dict from torch.nn import functional as F def sample_logits(out: torch.Tensor, temperature: float = 1.0, top_p: float = 0.8, logit_bias: Dict[int, float] = None) -> int: probs = F.softmax(out.cpu(), dim=-1).numpy() return sample_probs(probs, temperature, top_p, logit_bias) def sample_probs(probs: np.ndarray, temperature: float = 1.0, top_p: float = 0.8, logit_bias: Dict[int, float] = None) -> int: assert 0.0 <= temperature, 'temperature' assert 0.0 <= top_p <= 1.0, 'top_p' if top_p == 0.0: top_p = 1.0 if logit_bias is not None: logits = np.log(probs) for token in logit_bias.keys(): logits[token] += logit_bias[token] probs = np.exp(logits) / np.sum(np.exp(logits)) if temperature == 0.0: return np.argmax(probs).item() if top_p < 1.0: sorted_probs = np.sort(probs)[::-1] cumulative_probs = np.cumsum(sorted_probs) cutoff = float(sorted_probs[np.argmax(cumulative_probs > top_p)]) probs[probs < cutoff] = 0 if temperature != 1.0: probs = np.power(probs, 1.0 / temperature) probs = probs / np.sum(probs) return np.random.choice(a=len(probs), p=probs)