theano_exp.py

#Import needed libraries
import theano 
from theano import tensor 
#Define sigmoid function
def sigmoid(x):
  return 1 / (1 + tensor.exp(-x))
#Creating a symbolic variable
a = tensor.dmatrix('a') 
#Get sigmoid of a 
sig_a = sigmoid(a) 
#Apply functiom 
log = theano.function([a], sig) 
#Call log function for specific values 
print(log([[0, 1], [-1, -2]]))