Relational expressions in MATLAB

Introduction

Relational expressions help you compare values to see if one is bigger, smaller, or equal to another. This is useful to make decisions in your program.

Checking if a number is greater than a limit before proceeding.

Comparing two variables to see if they are equal.

Finding out if a value is less than or equal to a threshold.

Filtering data by selecting only values that meet a condition.

Controlling loops that run while a condition is true.

Syntax

MATLAB

result = (value1 operator value2);

% Operators:
% ==  Equal to
% ~=  Not equal to
% >   Greater than
% <   Less than
% >=  Greater than or equal to
% <=  Less than or equal to

The result is always logical: true (1) or false (0).

Use parentheses to make the comparison clear and avoid mistakes.

Examples

This checks if a is less than b. The result will be true because 5 is less than 10.

MATLAB

a = 5;
b = 10;
result = (a < b);

This checks if x is equal to y. The result will be true because both are 7.

MATLAB

x = 7;
y = 7;
result = (x == y);

This checks if score is greater than or equal to pass_mark. The result will be true because 85 is more than 60.

MATLAB

score = 85;
pass_mark = 60;
is_pass = (score >= pass_mark);

Sample Program

This program compares two numbers a and b. It prints a message if a is less than b. Then it checks if they are equal and shows the result.

MATLAB

a = 12;
b = 20;

if a < b
    disp('a is less than b');
else
    disp('a is not less than b');
end

is_equal = (a == b);
disp(['Are a and b equal? ', mat2str(is_equal)]);

Important Notes

Relational expressions return logical values: 1 for true and 0 for false.

You can use relational expressions inside if statements to control program flow.

Remember to use == for equality, not = which is for assignment.

Summary

Relational expressions compare two values and return true or false.

Common operators include ==, ~=, >, <, >=, and <=.

They are useful for making decisions and controlling program flow.