#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
ENGG1811 Lecture 

numpy elementwise additional, subtraction, multiplication, division
and exponentiation 
"""
import numpy as np 

array1 = np.array([ [-3.2,  0,  0.5, 5.8], 
                    [   6, -4,  6.2, 7.1],
                    [ 3.8,  5,  2.7, 3.7]])

array2 = np.array([ [-1.2,  2, -3.1, 0.0], 
                    [   4, -5,  3.5, 7.1],
                    [ 2.7,  2,  1.7, 3.4]])


# %% Two arrays of the same dimension 
array_add = array1 + array2 
array_sub = array1 - array2
array_mul = array1 * array2
array_div = array1 / array2 # divide by 0 error 
array_power = array1 ** array2 
# There is a warning because -3.2 ** -1.2 is not a real
# number. 

# Alternative forms 
array_add_alt = np.add(array1,array2)
array_mul_alt = np.multiply(array1,array2)
array_div_alt = np.divide(array1,array2)  
array_power_alt = np.power(array1,array2)

# %% An example
array1 / (array1 + array2)