How to Check if array has multiples of a value and how to replace those values that are multiples with a certain assigned values

This is the Question:

1. Check each value in the Z array to see if it is a multiple of 8. If an element is a multiple of 8, assign -6 to that element.
2. The only thing you are to display in the Command window is the Z array values.

T

if mod(Z(m),8)==0 && mod(Z(m),8)==0

Z(m,n)=-6

end

Z

ans=

4 6 8 0

6 8 10 0

8 10 12 42

0 0 105 -6

Answer 1

[KSSV]

If A is your matrix.

idx = mod(A,8)==0 ; % get indices which are divisible by 8
A(idx) = -6 ;   % repalce the values 

[Shanzeh Aftab]

It says incorrect use of = for the first command

[Shanzeh Aftab]

Also its giving an error for idx

[KSSV]

Show us the hwole code which you have tried.

[Shanzeh Aftab]

clear;clc

U = ones(3,3);
U = U*2;
for m= 1:4
    for n= 1:4
       W(m,n)= m+n;
    end
       U(3,4)=6
        U(4,3)=15
        for Z= U.*W
        if mod(Z(m),8)==0 && mod(Z(n),8)==0;
            Z(m,n)=-6
        end
      end 
end 
Z
            

[KSSV]

What is that code man ? You should read basics of MATLAB first. There are lot of erros in the code. You should follow something like this.

clear;clc
U = ones(4);
U = U*2;
for m= 1:4
   for n= 1:4
      W(m,n)= m+n;
    end
end
Z= U.*W ;
idx = mod(Z,8)==0 ;
Z(idx) = -6 ;

[Shanzeh Aftab]

I used the code you offered for where my mod command is. Since I am in an introductory level class I can only work with a simpel mod command. Also I am working towards fixing my code in the beginning since that might be messing my answer up

[Shanzeh Aftab]

LOL sorry to dissappoint but I am not a coding major to begin with. I have been forced by my school to take a computational data science course as part of my degree and I have no background in programming whatsoever so bare with me if possible.

[Shanzeh Aftab]

Btw it worked so thank you for your help

[KSSV]

Coding is easy...don't think your school forced you to take it. Try to learn and enjoy.

Thanks is accepting/ voting the answer. :)