Matlab/Octave

Function Definition and Execution

In this page, I will explain on how to define a user defined Matlab function (meaning your own function) and how to call (execute) the function.

Function Definition and Execution in a same file - Typical Definition

The most typical way of defining and executing a function is to define a function in a file (*.m) and call (execute) the function in another file (*.m) or command line as in the following examples.

< Example 1 >

Step 1 : Save following code in a file named myAdd.m (Name the file name same as function name

function r = myAdd(a,b)

   r = a + b;

Step 2 : Save following code in another file (example, fTest.m)

c = myAdd(2,4)

Step 3 : Run fTest.m

r1 = myAdd(2,4)

r2 = myAdd([1 2 3],[4 5 6])

 

you will get the result as follows.

 

r1 =

 

     6

 

 

r2 =

 

     5     7     9

Function Definition and Execution in a same file

You can define a function and execute the function in a same file as shown in the following example

Step 1 : Create a file as shown below (In this example, I save the code in InFileFunction.m)

function main

   c = myMultiply(2,4)

   d = myDivide(2,4)

end

 

function y=myMultiply(a,b)

    y = a * b;

end

 

function y=myDivide(a,b)

    y = a / b;

end

Step 2 : Run the saved file (InFileFunction.m) and you will get the result as follows.

c =

 

     8

 

 

d =

 

    0.5000