function [fvec,J] = meyer(n,m,x,opt)% ************************************************% ************************************************             % function [fvec,J]= meyer(n,m,x,opt)% Meyer function   [10]% Dimensions   n=3   m=16% Function definition:%       f(x) = x(1)*exp[x(2)/(t(i) + x(3))]-y(i)%       where t(i)= 45 + 5i% Standard starting point at x=(0.02,4000,250)% Minima of f=87.9458...%% Revised 10/23/94      PLK% ************************************************      zero = 0.d0;      one = 1.d0;      y = [ 34780.d0      28610.d0      23650.d0      19630.d0      16370.d0      13720.d0      11540.d0      9744.d0      8261.d0      7030.d0      6005.d0      5147.d0      4427.d0      3820.d0       3307.d0       2872.d0 ]' ;            x1 = x(1);      x2 = x(2);      x3 = x(3);    if opt==1      for i = 1: m        ti = (45+5*i);        di = ti + x3;        ei = exp(x2/di);        fvec(i) = (x1 * ei) - y(i);      end      fvec=fvec';    elseif opt==2      for i = 1: m        ti = (45+5*i);        di = ti + x3;        qi = one / di;        ei = exp(x2*qi);        si = x1*qi*ei;        J(i,1) =  ei;        J(i,2) =  si;        J(i,3) = -x2*qi*si;      end     elseif opt==3      for i = 1: m        ti = (45+5*i);        di = ti + x3;        qi = one / di;        ei = exp(x2*qi);        si = x1*qi*ei;        fvec(i) = (x1*ei) - y(i);        J(i,1) =  ei;        J(i,2) =  si;        J(i,3) = -x2*qi*si;      end      fvec=fvec';     else        disp('Error: Option value sent to MEYER.M is either <1 or >3');     end;