How to Call a Function in MATLAB: Syntax and Examples

In MATLAB, you call a function by typing its name followed by parentheses containing any input arguments, like result = myFunction(input1, input2). If the function returns outputs, assign them to variables; otherwise, just call the function by its name and inputs.

Syntax

The basic syntax to call a function in MATLAB is:

• output = functionName(input1, input2, ...) - calls the function with inputs and stores the output.
• functionName(input1, input2, ...) - calls the function without storing output.

Here, functionName is the name of the function, input1, input2 are input arguments, and output is the variable to store the result.

matlab

output = functionName(input1, input2, ...)

functionName(input1, input2, ...)

Example

This example shows how to call a function named addNumbers that adds two numbers and returns the sum.

matlab

function sum = addNumbers(a, b)
    sum = a + b;
end

% Calling the function
result = addNumbers(5, 3);
disp(['The sum is: ', num2str(result)])

Output

The sum is: 8

Common Pitfalls

Common mistakes when calling functions in MATLAB include:

• Not using parentheses when calling a function, which causes errors.
• Forgetting to assign output if the function returns a value you want to use.
• Passing wrong number or type of input arguments.

Always check the function definition to know how many inputs and outputs it expects.

matlab

% Wrong: missing parentheses
% result = addNumbers 5, 3

% Right: use parentheses
result = addNumbers(5, 3);

Quick Reference

Here is a quick summary of calling functions in MATLAB:

Action	Syntax Example
Call function with output	result = functionName(input1, input2)
Call function without output	functionName(input1, input2)
Call function with no inputs	output = functionName()
Call function with multiple outputs	[out1, out2] = functionName(input)

Key Takeaways

Call a MATLAB function by typing its name followed by parentheses with inputs.

Assign outputs to variables if you want to use the returned values.

Always use parentheses even if the function has no inputs.

Check the function definition for correct number of inputs and outputs.

Avoid common mistakes like missing parentheses or wrong argument counts.