How to compare and process the Array elements using Numpy in Python Program

Python Program to compare and process the Array elements using Numpy Package

# Importing the 'numpy' package

import numpy

from numpy import *

# Creating arrays using array() function:

ary1 = array([1, 2, 3, 4, 5], int)

ary2 = array([0, 2, 7, 4, 1])

print('The array1:', ary1)

print('The array2:', ary2)

Output:

The array1: [1 2 3 4 5]

The array2: [0 2 7 4 1]

# Mathematical Operations on Arrays:

ary3 = ary1+3

ary4 = ary1+ary2

print('The result of ary1+3:', ary3)

print('The result of ary1+ary2:', ary4)

Output:

The result of ary1+3: [4 5 6 7 8]

The result of ary1+ary2: [ 1  4 10  8  6]

# Logical comparison of arrays:

c1 = (ary1 == ary2)

c2 = (ary1 <= ary2)

print('the result of ary1==ary2:', c1)

print('the result of ary1<=ary2:', c2)

Output:

the result of ary1==ary2: [False  True False  True False]

the result of ary1<=ary2: [False  True  True  True False]

# Checking all() or any() of the element is true:

print('Check if any one element is true:', any(c2))

print('Check if all the elements are true:', all(c2))

Output:

Check if any one element is true: True

Check if all the elements are true: False

# Logical functions of arrays:

a = array([1, 2, 3, 5])

b = array([3, 0, 2, 7])

c = logical_not(a)

d = logical_and(a >= 2, a < 4)

e = logical_or(b > 0, b <= 2)

print('The result of logical_not is:', c)

print('The result of logical_and is:', d)

print('The result of logical_or is:', e)

Output:

The result of logical_not is: [False False False False]

The result of logical_and is: [False  True  True False]

The result of logical_or is: [ True  True  True  True]

# Comparing two arrays and return bigger elements to another array:

a = array([10, 15, 13, 23, 33])

b = array([7, 17, 11, 25, 27])

c = where(a > b, a, b)

print('Compare a and b then return bigger elements:', c)

Output:

Compare a and b then return bigger elements: [10 17 13 25 33]

# Finding the index of non-zero elements:

ary1 = array([1, 0, 3, 4, 0, 7, 9], int)

i = nonzero(ary1)

print('The array elements are:', ary1)

# display the index of non-zero elements

print('The non zero element found at indexes:')

for j in i:

    print(j)

# display the non zero elements

print('\nThe non zero elements are:', ary1[i])

Output:

The array elements are: [1 0 3 4 0 7 9]

The non zero element found at indexes:

[0 2 3 5 6]

The non zero elements are: [1 3 4 7 9]

# Aliasing the Arrays:

ary1 = array([1, 0, 3, 4, 0, 7, 9], int)

ary2 = ary1  # aliasing the array

ary2[1] = 99  # if effects in both ary1 and ary2

print('The original array:', ary1)

print('The alias array:', ary2)

Output:

The original array: [ 1 99  3  4  0  7  9]

The alias array: [ 1 99  3  4  0  7  9]

# Viewing and Copying the Arrays:

ary1 = array([1, 0, 3, 4, 0, 7, 9], int)

ary2 = ary1.view()  # creating a view of ary1 and call into ary2

ary2[1] = 99  # if effects in both ary1 and ary2

print('The original array:', ary1)

print('The alias array:', ary2)

Output:

The original array: [ 1 99  3  4  0  7  9]

The alias array: [ 1 99  3  4  0  7  9]

# Slicing and Indexing array elements:

a = arange(10, 16)

print('The array a of range 10 to 16:', a)

n = len(a)

print('The size n of array a is:', n)

# start=1, stop=(6-1), step=2

b = a[1:6:2]

print('The sliced array from a is:', b)

Output:

The array a of range 10 to 16: [10 11 12 13 14 15]

The size n of array a is: 6

The sliced array from a is: [11 13 15]

# start=(n-2)=4, stop=(2-1), step=-1(decreasing size)

b = a[-2:2:-1]

print('The sliced array from a is:', b)

Output:

The sliced array from a is: [14 13]

# start=0, stop=(n-2)-1=3, step=0

b = a[:-2:]

print('The sliced array from a is:', b)

Output:

The sliced array from a is: [10 11 12 13]

# Retrieving all the elements from a

c = a[::]

print('The array c:', c)

Output:

The array c: [10 11 12 13 14 15]

#--------------------------------------------------------------Thanks--------------------------------------------------------------#