function[tset]=settling_time(g,stardard)
%This function compute settling time, input data is tranfer function, error
%stardard (0.02 or 0.05 or other) if stardard=null, I get: stardard=2%
%-------------------------------------------------------|%
%|(C)2005 Bui Trung Hieu				|%
%|Website: www.khvt.com					|%
%|Email: matlab@khvt.com				|%
%-------------------------------------------------------|%

gtxl=freqresp(g,0);
if(nargin==1)
    stardard=0.02;
end
    
ymin=gtxl*(1-stardard);
ymax=gtxl*(1+stardard);
[y,t]=step(g);
for k=length(y):-1:1
    if ((y(k)>ymax)|y(k)<ymin)
        tset=t(k);
        break;
    end
    if (k==1)
        error('Loi nhap du lieu!')
        tset=null;
    end
end
clear y t ymin ymax