Question

in matlab

(a)Write a function to generate n random integers between -b and b.

(b) Using the function you wrote in (a) generate 50 random numbers in a vector A where b = 100;

(c) This array A will contain both negative, positive and possibly zero entries. Write a MATLAB script to compute the percentage of positive, negative and zero entries in the array.

Answer 1

Question (a)

The MATLAB Function is written as follows

function [A] = myrandfunc(n, b)
% MYRANDFUNC generates n random numbers between-b and +b
% n = Number of random numbers to be generated
% b = This gives the range [-b, b] in which the random number is to be generated
% A = Output of the function containing the n random numbers

range = [-b, b]; % The Range
A = randi(range, n, 1); % Generating n random numbers

end

This is saved with the same name myrandfunc

Question (b)

The function is called as follows in the command prompt

After entering this command, we will get the result as follows

>> A = myrandfunc(50, 100)

A =

94
52
82
77
-69
33
-67
2
54
-73
78
0
-35
95
51
14
64
46
-55
-58
-38
4
14
46
-80
-48
-45
39
88
-79
67
-69
32
77
95
-81
40
-74
20
-55
-42
-21
-69
55
-55
-49
57
-84
-74
-2

>>

So we can see 50 random integers between -100 and 100

Question (c)

MATLAB Code

clc;
clear all;

n = input('Enter the number of random integers to be generated: ');
b = input('Enter the value of b: ');

A = myrandfunc(n, b);

np = 0; % Initialize number of positive integers to 0
nn =0; % Initialize number of negative integers to 0
nz = 0; % Initialize number of zeros to 0

for n = 1:n
if A(n) > 0
np = np + 1;
elseif A(n) < 0
nn = nn +1;
else
nz = nz + 1;
end
end

P = np/n*100;
N = nn/n*100;
Z = nz/n*100;

fprintf('The percentage of positive integers generated is %f \n', P);
fprintf('The percentage of negative integers generated is %f \n', N);
fprintf('The percentage of zeros generated is %f \n', Z);

After executing, we can enter the number of integers to be generated and the range as follows

Enter the number of random integers to be generated: 50
Enter the value of b: 100
The percentage of positive integers generated is 40.000000
The percentage of negative integers generated is 58.000000
The percentage of zeros generated is 2.000000
>>

Another Code:

clc;
clear all;

n = input('Enter the number of random integers to be generated: ');
b = input('Enter the value of b: ');

A = myrandfunc(n, b);

pi = find(A>0); % Find the indices of positive integers in A
ni = find(A<0); % Find the indices of negative integers in A
zi = find(A==0); % Find the indices of zeros in A

np = length(pi); % Find the number of positive integers
nn = length(ni); % Find the number of negative integers
nz = length(zi); % Find the number of zeros

P = np/n*100; % Calculate the percentage of positive numbers   
N = nn/n*100; % Calculate the percentage of negative numbers
Z = nz/n*100; % Calculate the percentage of zeros

fprintf('The percentage of positive integers generated is %f \n', P);
fprintf('The percentage of negative integers generated is %f \n', N);
fprintf('The percentage of zeros generated is %f \n', Z);

After executing, we can enter the number of integers to be generated and the range as follows

Enter the number of random integers to be generated: 50
Enter the value of b: 100
The percentage of positive integers generated is 42.000000
The percentage of negative integers generated is 56.000000
The percentage of zeros generated is 2.000000
>>