Question

In this problem you will need to read about the functions numpy.load and numpy.bincount. Store all answers in appropriate variables. numbers = np.load('randomints.npy')

Use only numpy functionality to carry out this part.

(a) Load the file randomints.npy into a numpy array. There are 100000 integers in this file and they are between 0 and 1000.

(b) Get a bincount array for the array loaded in the first part.

(c) Let M be the largest number of times an element occurs in the array.

What is the smallest number that occurs M times?

(d) What is the number of integers that occurred 111 times?

Answer 1

Solution: It has been assumed that the 'randomints.npy' file already exist. In case it does not exist and you would like to create the same, please run the following Code 1 one time only. (Please do not run this one time code if the file already exists)

Hope that helps.

Code 1 (one time code)

import numpy as np
import random

#Empty list
lst_int = []
#Add 100000 random numbers to the list 
for i in range(100000):
        lst_int.append(random.randint(0,1000))

# converting list to array
arr = np.array(lst_int)

np.save('randomints.npy',arr)

Main Solution to the various points have been given below :

The code has been tested it on a file with 10 random integers. The output has been given for the same. The code will work for 100000 random integers without any amendments.

#import
import numpy as np

# Problem Part a
# Load the file contents to an arrary b
b = np.load('randomints.npy')

#Print the array 
print("Array from the file")
print (b)

#Get the corresponding bin_count array
print("Bin Count Array")
b_bit = np.bincount(b)

#Print the bin count array
print(b_bit)

#Maximum number of times an integer occurs M
#This can be found from the bincount array which stores occurances
M = np.max(b_bit)

#Print value of M for reference
print(f"Maximum Number of times: {M}")

#Enumerate the Bin Count array  
#Break on the first index 
#This will give the minimum number which occur
#Variable min_M will hold the value

for idx, x in np.ndenumerate(b_bit):
    if x == M:
        number = idx
        min_M = number[0]
        break

print(F"Minimum number which occurs Maximum times: {min_M}")

#Find number of integers which occured 111 times
#We will store this sum in OCC_111 variable

OCC_111 = 0

for idx, x in np.ndenumerate(b_bit):
    if x == 111:
        OCC_111 = OCC_111 + 1

print (f"Number of integers which occur 111 times : {OCC_111}")

Output

Array from the file
[10 3 10 3 6 2 5 3 5 5]
Bin Count Array
[0 0 1 3 0 3 1 0 0 0 2]
Maximum Number of times: 3
Minimum number which occurs Maximum times: 3
Number of integers which occur 111 times : 0