CODEWITHSUNDEEP
matlablogiclogical-operators
Rabea
Rabea

Reputation: 13

Programming in matlab with logical conditions

I have a little logical problem that I would like to have solved someday!! Let's say you have 4 variables, I will call them a, b, c and d. Now based on some logic the following conditions are given.

The program passes:

the program fails:

So if you fill in one variable you are forced to fill in more. If you don't fill in any variable no action is needed.

To keep it simple I said that 1 equals filled and 0 equals not filled. My piece of code is not working correctly because if I say that only d is filled it gives back that this is okay. But it shouldn't work since only d is a fail.

Any idea's what I could do? Maybe my way of thinking about this is not correct? Keep in mind that the 0 and 1 are just to keep this simple, so adding a sum would not help!

Here is my code: 

a = 0; 
b = 0; 
c = 0; 
d = 1; 

if a ~=0 || b ~=0 || c ~=0 || d ~=0
    if ~(a~=0 || b~=0 && c~=0 || d~=0 ) 
       works = 1;
    else
       no = 1;
    end
end

Thank you for reading!

Upvotes: 0

Views: 147

Answers (2)

Nicky Mattsson
Nicky Mattsson

Reputation: 3052

As the question is tagged MATLAB I will also give you a MATLAB solution. Basically your idea of adding a sum is just the way to go, just convert your variables to binary first, which is done with logical. Thus the check for fail can be done with

arr = logical([a,b,c,d]);
fail = sum(logical(arr))==1 || all(arr(1:2))

Where the first condition checks how many have been filled and the second checks whether a and b are both set.

One should note, that there are cases that satisfy both pass and fail conditions (e.g. all variables set). The solution above is fail greedy. A pass greedy solution would be (as proposed by Cris Luengo in the comments)

arr = logical([a,b,c,d]);
fail = sum(logical(arr))==1 || all(arr==[1,1,0,0])

Upvotes: 1

Keijack
Keijack

Reputation: 868

If you want your code is more readable, you can use a method to do the logic, and the easiest way to do it just translate your logic. 

public static boolean isParamFilled(boolean a, boolean b, boolean c, boolean d) {
    if ((a || b) && (c || d)) return true;
    if (c && d) return true;
    int ia = a ? 1 : 0;
    int ib = b ? 1 : 0;
    int ic = c ? 1 : 0;
    int id = d ? 1 : 0;
    // Only one of the 4 parameters is filled.
    if (ia + ib + ic + id == 1) return true;
    if (a && b) return false;
    // default value
    return false;
}

public static void main(String...args) {
    boolean a = false; 
    boolean b = false; 
    boolean c = false; 
    boolean d = true; 

    booledan worked = isParamFilled(a, b, c, d);
}

Upvotes: 1

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