how to write code for controller

Hi everyone; Can anyone guide me the simple steps that how can I write my own code for pid controller without using any built in command. Please guide me.

Answer 1

[Walter Roberson]

You cannot do that. See http://www.mathworks.co.uk/matlabcentral/answers/38787-what-can-be-programmed-without-any-built-in-functions

[azan]

I have seen many codes on pid controller in which input is step or ramp I haven't seen a single code in which input to pid is a scalar quantity and output is shown for that. I was having no idea that is it possible to write such code for pid controller. According to my experience it is not always necessary to use built in commands one can also write the code without using them.

[Walter Roberson]

Did you read the link I gave? It lists the kinds of code that it is possible to write in MATLAB without using any built-in commands. PID controllers are not possible without using an built-in commands.

[azan]

ok sir now I got the point but using the built in commands for pid controller is it possible to give it a scalar input rather than ramp or step.