Is it possible to skip for loop when error appears and replace the results with NaN?

I have a 3D matrix ( Auto) and in which I am fitting the Auto(p,q,:) elements using a for a loop. I am calculating one parameter ( D(p,q)=fit1.D) from the fitting. However, due to some reason ( Complex value computed by model function, fitting cannot continue), fitting is not happening for some p,q and hence the for loop terminated. Here I want to put D(p,q)=NaN when the fitting gives the error and want to proceed for next loop.

Thanks in advance for your help.

 l2= size(Auto);
 for p=1:l2(1)
     for q=1:l2(2)
         y=reshape(Auto(p,q,2:end),[],1);
         x=(0:0.5:(35-1)*0.5)';
         f = fittype('(A./(sqrt(1+ ((x*D)./(0.251.^2)))))');
         fit1 = fit(x,y,f,'StartPoint',[0.1 0.1 ]);
         D(p,q)=fit1.D;
   % D(p,q)=NaN;
      end
end

Answer 1

[James Tursa]

Something like this?

try
    % your fitting stuff goes here
    D(p,q) = fit1.D;            
catch
    D(p,q) = NaN; 
end

[Jaladhar Mahato]

Thanks, James for your quick reply.

It is indeed a great trick. I have faced this many times but somehow I overcome this. I think it will help a lot of other users. The only problem with my data is that in most of the cases fitting is not happening (Which becomes vivid from a lot of NaN values in the output). Thanks again.