Source code for nachos.similarity_functions.gaussian

import numpy as np
from nachos.similarity_functions.abstract_similarity import AbstractSimilarity
from nachos.similarity_functions import register


[docs]@register('gaussian') class Gaussian(AbstractSimilarity):
[docs] @classmethod def build(cls, conf: dict): return cls(conf['Gaussian_thresh'])
[docs] def __init__(self, t: float): super().__init__() self.thresh = t
[docs] def __call__(self, f: set, g: set) -> float: ''' Summary: Computes the thresholded similarity score between inputs f, g. f, g are assumed to be real valued scalars, and the similarity is the Gaussian similarity between the values assuming unit variance. Inputs ------------------------------------ :param f: a float representing a real value to compare :type f: float :param g: a float representing a real value to compare :type g: float Returns -------------------------------------- :return: returns the similarity score :rtype: float ''' # If there is more than one real value in f, g, we just take the average sim = np.exp(-(float(sum(f)/len(g)) - float(sum(g)/len(g)))**2) return float(sim if sim > self.thresh else 0)