GPy/GPy/util/squashers.py

# Copyright (c) 2012, GPy authors (see AUTHORS.txt).
# Licensed under the BSD 3-clause license (see LICENSE.txt)


import numpy as np

def sigmoid(x):
    return 1./(1.+np.exp(-x))

def softmax(x):
    ex = np.exp(x-x.max(1)[:,None])
    return ex/ex.sum(1)[:,np.newaxis]

def single_softmax(x):
    ex = np.exp(x)
    return ex/ex.sum()