MATLAB: How to turn s/s to 1

symbolic

I run this code and if I click yes without change anything in the inputdlg, I receive 's/s'. How can I return this to '1' in this situation?
 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);
        evalc('handles.PID_sys')
end 
end

Best Answer

 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
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