شبیه سازی برج تقطیر با کنترلر PI
function [ret,x0,str,ts,xts]=colas_PI(t,x,u,flag);
%COLAS_PI is the M-file description of the SIMULINK system named COLAS_PI.
% The block-diagram can be displayed by typing: COLAS_PI.
%
% SYS=COLAS_PI(T,X,U,FLAG) returns depending on FLAG certain
% system values...