function[Kc]=Kc_error(g,k)
%Kc=Kc_error(g,k)
%Assume that: 
%If tf have no ideal integral, k=Kp
%If tf have 1 ideal integral, k=Kv
%If tf have 2 ideal integral, k=Ka
%-------------------------------------------------------|%
%|(C)2005 Bui Trung Hieu				|%
%|Website: www.khvt.com					|%
%|Email: matlab@khvt.com				|%
%-------------------------------------------------------|%
if (nargin==2)
    if(length(k)==1)
        sw=length(find(pole(g)==0));
        if (sw==0)
    %This code to find Kc from Kp
            a=dcgain(g);
            Kc=double(k/a);
        elseif (sw==1)
    %This code to find Kc from Kv
            s=tf('s');
            a=dcgain(minreal(s*g));
            Kc=double(k/a);
        elseif (sw==2)
    %This code to find Kc from Ka
            s=tf('s');
            a=dcgain(minreal(s^2*g));
            Kc=double(k/a);
        end
    else
        Kc=[];
        error('???Ban nhap sai so chieu cua k!!!');        
    end
else
    Kc=[];
    error('???Xem help de co them thong tin!!!');
end