prompt={'Proportional Coefficient Input','Integral Coefficient Input','Derivative Coefficient Input'};
defans={'1','0','0'};
answer=inputdlg(prompt,'PID Coefficient Input',1,defans,'on');
if (~isempty(answer))
if (~isempty(answer{1}))&(~isempty(answer{2}))&(~isempty(answer{3}))&(answer{1}~='0')
syms s
x1=str2num(answer{1});
x2=str2num(answer{2});
x3=str2num(answer{3});
handles.pid(1)=x1(1);
handles.pid(2)=x2(1);
handles.pid(3)=x3(1);
handles.PID_num=[handles.pid(3),handles.pid(1),handles.pid(2)];
handles.PID_den=[1,0];
handles.PID_sys=tf(handles.PID_num,handles.PID_den);
[num,den] = tfdata(handles.PID_sys);
if(num{:}==den{:})
handles.PID_sys=1;
end
evalc('handles.PID_sys')
end
end
