e691.m

matlab算法集 matlab算法集

%------------------------------------------------------------------------
% Example 6.9.1: Heat Exchanger 
%------------------------------------------------------------------------

% Initialize

   clc                    % clear screen
   clear                  % clear variables
   global  r t y          % used in funf691.m
   r   = 16;              % number of data points
   n   = 3;               % number of variables 
   m   = 1500;            % maximum iterations 
   p   = 10*r;            % number of plot points 
   tol = 1.0e-5;          % error tolerance 
   T   = 30;              % range of t (min) 
   q   = [7.2 4.0 3.2]';  % nominal parameters 
   x0  = [3 3 3]';        % initial guess 
   X   = zeros (p,2);
   Y   = zeros (p,2);
   t   = zeros (r,1);
   y   = zeros (r,1);
   d   = fopen('e691.dat','w');		

% Construct data 

   fprintf ('Example 6.9.1: Heat Exchanger\n');
   randinit (100);
   for i = 1 : r
      t(i) = (i-1)*T/(r-1);
      y(i) = fung691 (t(i),q) + randu(1,1,-0.1,0.1);
   end
   for i = 1 : r/2
      fprintf (d,'\n %.0f & %.3f & %.0f & %.3f \\\\', ...
               t(i),y(i),t(r/2+i),y(r/2+i)); 
   end
   fclose (d);

% Find curve fit parameters 
      
   disp ('Finding parameters ... ') 
   [x,ev,j] = conjgrad (x0,tol,n,m,'funf691');
   show ('x',x);
   show ('f(x)',funf691(x));
   show ('function evaluations',ev)
      
% Display curves and data 

   for i = 1 : p
      j = min ([i,r]);	
      X(i,1) = (i-1)*T/(p-1);
      Y(i,1) = fung691 (X(i,1),x); 
      X(i,2) = t(j);
      Y(i,2) = y(j);
   end
   graphxy (X,Y,'','t (min)','y (deg)','s')
%------------------------------------------------------------------------