draw a control plot for a function

hello everyone, I need to generate a contour plot for the following code:- e=2.71828; dt=.01; A=-1; B=1; a=cell(12,12); data=zeros(1,220) for i=1:20 eps=i for j=0:0.1:1 beta=j for t=0:0.01:1.9 t=t+dt xp=0.1 fxp=eps*xp fz0=1/1+power(e,beta*(-t)) fzi=A+(B-A)*rand(1,12) for ii=1:12 for jj=1:12 if ii==jj a2(ii,jj)=fzi(jj) else a2(ii,jj)=0; end end end s=fxp*fz0 *a2 x=xp+(s*dt) xp=x end p=abs(fft(x)) p=p.^2 ne=max(p(1:10)) ne1=max(p(10:30)) ne2=max(p(80:120)) end end figure (1) [C,h]=contour(eps,beta,ne,'linewidth',2) figure (2) [C,h]=contour(eps,beta,ne1,'linewidth',2) figure (3) [C,h]=contour(eps,beta,ne2,'linewidth',2)

ne,ne1,ne2 is holding the value only for the last loop..but i need all the values of ne,ne1,ne2.. what should i do..please help....

Answer 1

[A Jenkins]

You want to store ne, etc as a matrix of the size of your loops, so it would be ne(i,j), etc:

   e=2.71828; 
   dt=.01; 
   A=-1; B=1; 
   a=cell(12,12); 
   data=zeros(1,220);
   eps=1:20;
   beta=0:0.1:1;
   kk=0;
   for i=1:length(eps) 
       for j=1:length(beta)
           for t=0:0.01:1.9 
               t=t+dt;
               xp=0.1; 
               fxp=eps(i)*xp ;
               fz0=1/1+power(e,beta(j)*(-t)); 
               fzi=A+(B-A)*rand(1,12);
               for ii=1:12 
                   for jj=1:12 
                       if ii==jj 
                           a2(ii,jj)=fzi(jj); 
                       else
                           a2(ii,jj)=0;
                       end
                   end
               end
               s=fxp*fz0 *a2;
               x=xp+(s*dt); 
               xp=x;
           end
           p=abs(fft(x)); 
           p=p.^2;
           ne(i,j)=max(p(1:10));
           ne1(i,j)=max(p(10:30));
           ne2(i,j)=max(p(80:120)); 
       end
   end
   figure(1) 
   [C,h]=contour(eps,beta,ne','linewidth',2) 
   figure(2) 
   [C,h]=contour(eps,beta,ne1','linewidth',2) 
   figure(3) 
   [C,h]=contour(eps,beta,ne2','linewidth',2)

[debabrat]

Thank you very much A Jenkins... It works nicely..