How to make a code continue running if while loop returns NaN

I have the following code below

 R =5; % LQR Weighting

 Q = [100 0 0 0; 0 5 0 0; 0 0 10 0; 0 0 0 1];

 K = dlqr(Adhat,Bdhat,Q, R);

 R1a = tf(ss(Adhat,Bdhat,K,0));

 T1a = minreal(minreal(R1a)/(1 + minreal(R1a))); % Closed Loop   Transfer Function

 figure(1)

 step(T1a)

 S = stepinfo(T1a,'SettlingTimeThreshold',0.01); %Settling time threshold specification for 1%

 x = S.SettlingTime;

 while x > 0.1

   R=R/2;

   Q = Q*2;

   K = dlqr(Adhat,Bdhat,Q, R);

    R1a = tf(ss(Adhat,Bdhat,K,0));

    T1a = minreal(minreal(R1a)/(1 + minreal(R1a)));

    figure(1)

    step(T1a)

    hold on

    x1 = 0:0.1:20; y1 = 1.01*ones(size(x1)); line(x1,y1) % Line to indicate +1%

    x2 = 0:0.1:20; y2 = 0.99*ones(size(x2)); line(x2,y2) % Line to indicate -1%

    hold off

    S = stepinfo(T1a,'SettlingTimeThreshold',0.01); %Settling time threshol specification for 1%

    x = S.SettlingTime;

 end

 figure(2)
 nyquist(R1a)
 title('Nyquist diagram of return ratio, K ')
 hold on
 circ = -1 +exp(j*[0:pi/1000:2*pi]');
 plot(circ,'r')
 hold off

 disp('See Fig 2')

 disp(['Settling Time= ' num2str(x)])

 disp(['R= ' num2str(R)])

 disp(['K= ' num2str(K)])

I need the code to continue running even if the while loop returns a NaN value, I cant seem to get this to work. I have tried using if else loop and it returns the same result.

I will apprciate any tips to get this issue resolved.

Thanks

[Jan]

Please format your code properly. See the "Markup" link on this page for explanations.

It would be easier to answer, if you omit all lines, which do not concern your problem. A WHILE loop does not return anything, so please explain, where the NaN appears. Do you mean, that x gets the value NaN?

Answer 1

[Jan]

I have only a faint idea of what your problem might be. Perhaps this helps:

while (x > 0.1) || isnan(x)

[Adeyemi Adepegba]

Excellent answer, that solved the problem.

I dont understand your comment about editing the code.

Answer 2

[Sean de Wolski]

while something || isnan(something_else)
 %etc.
end

[Adeyemi Adepegba]

Thank you