Sub Functions
Sub functions are the functions that are defined after a primary function. Every function must be defined in a file except anonymous functions. Sub functions are defined in the primary function file and these functions are not visible to any other functions except the primary and sub functions that are defined within the file. Unlike primary functions, sub-functions can’t be accessed from command prompt/another file.
Syntax:
function output = mainFunction(x)
. . . . . .
subFunction(y)
. . . . . .
end
function result = subFunction(y)
. . . . . .
end
Example:
MATLAB
% Printing the sum of two numbers % using sub functions % Primary Function function result = adder(x,y) result = x+y; % Calling Sub function print(result); end % Sub function function print(result) fprintf( 'The addition of given two number is %d' ,result); end |
Save the above code with the primary function name adder.m and observe the output by calling it from the command prompt.
Output:
Functions in MATLAB
Methods are also popularly known as functions. The main aim of the methods is to reuse the code. A method is a block of code which is invoked and executed when it is called by the user. It contains local workspace and independent of base workspace which belongs to command prompt. Let’s take a glance of method syntax.
Syntax:
function [y1, y2 ,y3 . . . . , yn] = functionName(arguments)
. . . . .
end
where, y1 . . . . yn are output variables.
MATLAB syntax is quite peculiar compared to other programming languages. We can return one or more values from a function. We can also pass one or more arguments/variables while calling a function. MATLAB functions must be defined in separate files and function name must match with the file name. Let’s also see the few more ways of defining a function as per the user needs.
- Anonymous Functions
- Sub Functions
- Nested Functions
- Private Functions
Now let’s dive into an example and understand how to define a basic function.
Example:
MATLAB
% A MATLAB program to illustrate % defining a function function result = adder(x, y, z) % This function adds the 3 input arguments result = x+y+z; end |
The comment line that is written just after the function statement works as the help text. Save the above code as adder.m and observe the output by calling it from the command prompt.
Output: