Source code for nlpatl.sampling.uncertainty.entropy

from typing import Tuple
from scipy.stats import entropy
import numpy as np

from nlpatl.sampling import Sampling


class EntropySampling(Sampling):
    """
    Sampling data points according to the entropy. Pick the highest N data points

    :param name: Name of this sampling
    :type name: str
    """

    def __init__(self, name: str = "entropy_sampling"):
        super().__init__(name=name)

    def sample(
        self, data: np.ndarray, num_sample: int
    ) -> Tuple[np.ndarray, np.ndarray]:

        num_node = min(num_sample, len(data))

        # Calucalte entropy
        entropies = entropy(data, axis=1)
        indices = np.argpartition(-entropies, num_node - 1)[:num_node]

        return indices, entropies[indices]