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Check the given number is amstrong number using Matlab

Problem

Write a program in matlab to check whether the given number is Amstrong or not.

Solution

An Armstrong number of three digits is an integer such that the sum of the cubes of its digits is equal to the number itself. For example, 371 is an Armstrong number since 3**3 + 7**3 + 1**3 = 371.
To know more about Amstrong number visit the references below.
To understand this program you need to know the following:
Function definition in Matlab
For loop in matlab
num2str function in matlab
length function in matlab
str2num function in matlab
logical function in matlab
Find the explanation of the program below the program section

Program


function answer = isamstrong(n)
%this function will give the result if the number is amstrong or not.

%First convert the number to a string to split and check for the condition.
n = num2str(n);

%Create a sum variable to find the sum of the cubes of each digit in the
%number and see if the number is equal to the given number or not.

sum = 0;

%Create a for loop to loop through all the digits and add them up
for i = 1: length(n)
    %Convert the string to number and raise it to the power 3
    %Add the number to the sum and in each loop this will get 
    %Added up and the final result will be there
    sum = sum+ (str2num(n(i)))^3;
end

if sum == str2num(n)
    answer = logical(1);
else
    answer = logical(0);
end

To download the above program in matlab file format then click here: isamstrong.m

Explanation

First we will convert the number to string so that we can split the digits to numbers and then do math on that. For example we will convert the number 123 to '123' so that we will use the n(1) to reference the number 1 and so on to do math.
I have also created a sum variable to find the sum of the cubes of each digit in the number, so that the amstrong number condition is verified.
A for loop is also created to loop through the digits. Remember why we have converted the number to string.
The for loop range is from  1 to length of the number. Digging deep we will understand that the program is converting each digit into number again using the str2num function and cubing it and finally adding it to the sum variable.
So in the first iteration, the sum will be 1, second iteration it will be 9. third iteration it will be 36 in the case of 123 as input. which shows that the number is not amstrong, but for the computer to decide we will use the if else statement.
In the if else statement we will finally convert back the given number from string to number to check if the sum is equal to the given number and if it is answer is true, else it is false.

I think the explanation is easy to understand, but if you have any doubt or if you didn't understand anything, then please do contact me and I will make modifications according to that or will personally explain it to you, so that it will be beneficiary to you and others also. You can contact me by clicking here: Contact me

The above code was high lighted using hilite.me

References:
Amstrong Numbers
Narcissitic Number
What is Amstrong Number - Yahoo Answer

Run the program and comment below the output you are getting for a given input.

 Keywords: amstrong number, matlab, if else
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