Function information_density

modAL/density.py:33–56

Calculates the information density metric of the given data using the given metric. Args: X: The data for which the information density is to be calculated. metric: The metric to be used. Should take two 1d numpy.ndarrays for argument. Todo: Should work with al

(X: modALinput, metric: Union[str, Callable] = 'euclidean')

def information_density(X: modALinput, metric: Union[str, Callable] = 'euclidean') -> np.ndarray:
    """
    Calculates the information density metric of the given data using the given metric.

    Args:
        X: The data for which the information density is to be calculated.
        metric: The metric to be used. Should take two 1d numpy.ndarrays for argument.

    Todo:
        Should work with all possible modALinput.
        Perhaps refactor the module to use some stuff from sklearn.metrics.pairwise

    Returns:
        The information density for each sample.
    """
    # inf_density = np.zeros(shape=(X.shape[0],))
    # for X_idx, X_inst in enumerate(X):
    #     inf_density[X_idx] = sum(similarity_measure(X_inst, X_j) for X_j in X)
    #
    # return inf_density/X.shape[0]

    similarity_mtx = 1/(1+pairwise_distances(X, X, metric=metric))

    return similarity_mtx.mean(axis=1)