""" NumPy is module for Python.

The name is an acronym for "Numeric Python" or "Numerical Python".

It is pronounced /ˈnʌmpaɪ/ (NUM-py) or less often /ˈnʌmpi (NUM-pee)).

It is an extension module for Python, mostly written in C.

This makes sure that the precompiled mathematical and numerical functions and functionalities of Numpy guarantee great execution speed.

"""

# THIS IS AN UNSTRUCTURED TEST FILE

import numpy as np

# Index trick when working with two np-arrays

a = np.array([1, 2, 3, 6, 1, 4, 1])

b = np.array([5, 6, 7, 8, 3, 1, 2])

# Only saves a at index where b == 1

other_a = a[b == 1]

# Saves every spot in a except at index where b != 1

other_other_a = a[b != 1]

# BOOLEAN INDEXING

x = np.array([4, 6, 8, 1, 2, 6, 9])

y = x > 5

print(x[y])

# >>> [6 8 6 9]

# Even shorter

x = np.array([1, 2, 3, 4, 4, 35, 212, 5, 5, 6])

print(x[x < 5])

# >>> [1 2 3 4 4]

# how you actually copy array without messing with the previous one

new_arr = b.copy()

#multidimensional array in numpy called matrix .(3x3) matrix

mymatrix = [[1,2,3] , [4,5,6] , [7,8,9]]

# generates 3 zeros in an array

myzeros = np.zeros(3)

# generates 4 ones in an array

myones = np.ones(4)

#creates an identity matrix uing numpy (4x4)

identitymatrix = np.eye(4)