Logical operators in MATLAB

In this article we see what are the logical operators in matlab and how they work as an example. First of all I remind you that MATLAB is a scripting language emulated by a development environment, it is used for numerical calculation purposes. As a reminder, logical operators allow you to form expressions that will tell your program what to do.
Our article is organized as follows.

• Logical operators in matlab
• Unary logical operators in MATLAB as an example
• Example of using binary operators in MATLAB
• The Ternary Operators in MATLAB : an example

Logical operators in matlab

Unary logical operators in MATLAB with examples

Logical negation (logical NOT) in MATLAB

It is a Boolean algebra unary logical operator and expresses a « state » in terms of conditions.

Example in MATLAB :

LOGICALVARIABLE = false;

if ~LOGICALVARIABLE
    disp("negation of variable is true")
else
    disp("negation of variable is false")
end

In MATLAB create a new script and run the selection by Editor > Run Selection

Another exemple of logical negation on a matrix in matlab :

MATRIX = eye(5)
disp(~MATRIX)

Operator all in MATLAB- determine if all array elements are nonzero or true

Like the title this operator will check among the first array dimension if all array element are non zero and it will return 0 for false or 1 for true.

Example :

SIMPLEARRAY = [2 1 3]
disp(all(SIMPLEARRAY))

SIMPLEARRAY = [1 1 1]
disp(all(SIMPLEARRAY))

SIMPLEARRAY = [0 0 0]
disp(all(SIMPLEARRAY))


MATRIXARRAY = [2 1 3;1 2 3;3 2 1]
disp(all(MATRIXARRAY))

MATRIXARRAY = [2 0 3;1 0 3;3 0 1]
disp(all(MATRIXARRAY))

MATRIXARRAY = [0 1 3;0 0 3;0 2 1]
disp(all(MATRIXARRAY))

Operator any in MATLAB- determine if any array elements are nonzero

Like the operator all, any operator will tests along the first array dimension of an array element and determines if any element is a nonzero number. It will return 0 for false and 1 for true.

You can take the code used before for all operator and replace it with « any » with replace all function :

SIMPLEARRAY = [2 1 3]
disp(any(SIMPLEARRAY))

SIMPLEARRAY = [1 1 1]
disp(any(SIMPLEARRAY))

SIMPLEARRAY = [0 0 0]
disp(any(SIMPLEARRAY))


MATRIXARRAY = [2 1 3;1 2 3;3 2 1]
disp(any(MATRIXARRAY))

MATRIXARRAY = [2 0 3;1 0 3;3 0 1]
disp(any(MATRIXARRAY))

MATRIXARRAY = [0 1 3;0 0 3;0 2 1]
disp(any(MATRIXARRAY))

The output of this script will be something like :

SIMPLEARRAY =

     2     1     3

   1


SIMPLEARRAY =

     1     1     1

   1


SIMPLEARRAY =

     0     0     0

   0


MATRIXARRAY =

     2     1     3
     1     2     3
     3     2     1

   1   1   1


MATRIXARRAY =

     2     0     3
     1     0     3
     3     0     1

   1   0   1


MATRIXARRAY =

     0     1     3
     0     0     3
     0     2     1

   0   1   1

>> 

Example of using binary operators in MATLAB

I will show you an example of using binary operators xor / & (and) / | (or) / && / ||. Here we are not exhaustive in relation to all the logical operators that can be binary in MATLAB. However, I think it’s a good base here and covers most use cases.

VARA = true;
VARB = false;
x = 11;

disp("AND = " + (VARA & VARB))
disp("AND = " + and(VARA,VARB))
disp("OR = " + (VARA | VARB))
disp("OR = " + or(VARA,VARB))
disp("XOR = " + xor(VARA,VARB))
disp("&& usage = " + ((x > 3) && (x < 10)))
disp("|| usage = " + ((x > 3) || (x < 10)))

Result is :

AND = false
AND = false
OR = true
OR = true
XOR = true
&& usage = false
|| usage = true
>> 

The Ternary Operators in MATLAB : an example

Matlab does not have a ternary operator by default, however you can create your own logical operator in MATLAB.

In this example we create a ternary operator which performs a test on condition and which returns a value if true in arg2 and if false in arg3.

Here is the example :

VARA = true;
TRUEVALUE = 56;
FALSEVALUE = 54;

x = 11;

ternaryCondition = @(arg1, arg2, arg3)...
    xor([false true], arg1) * [arg2; arg3];


disp(ternaryCondition(~VARA, TRUEVALUE, FALSEVALUE));
disp(ternaryCondition(VARA, TRUEVALUE, FALSEVALUE));
disp(ternaryCondition(VARA & true, TRUEVALUE, FALSEVALUE));

Result will be :

    54

    56

    56

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