How to use a function as builtin even if the matlab doesn't support the function as a builtin function?

How to use a function as builtin even if the matlab doesn't support the function as a builtin function?

[Stephen23]

Just declare the function and call it. Have you tried that?

Here is the documentation about defining and using functions:

http://www.mathworks.com/help/matlab/function-basics.html

[D Joseph]

But I don't have the definition of that function. I want it to use as a builtin function.

[Stephen23]

What function are you trying to use? If it is not a built-in function then you have to define it. This could include obtaining the function from a third party.

Can you please explain exactly what you are trying to do.

[D Joseph]

bwareafilt() function. I don't have the code to define it.