function [pout,fout] = linmin(pin,xi,tol,f,varargin)% PURPOSE: line minimization routine that performs an ad hoc n-dimensional%          Golden Section Search for the minimum of a function. %          (Converted from Numerical Recipes book linmin routine) %---------------------------------------------------% USAGE: [pout,fout] = linmin(pin,x,tol,func,varargin)% where:      pin = (kx1) vector of starting values%             x   = (kx1) direction vector%             tol = tolerance%            func = function name string%        varargin = arguments passed to func%---------------------------------------------------% RETURNS: pout = (kx1) minimizing vector%          fout = (kx1) value of func at minimum pout values%---------------------------------------------------% NOTE: func must take the form func(b,varargin)%       where: b = parameter vector (k x 1)%       varargin = arguments passed to the function               %---------------------------------------------------    % SEE ALSO: dfp_min, pow_min, frpr_min functions that use this routine%---------------------------------------------------% written by:% James P. LeSage, Dept of Economics% University of Toledo% 2801 W. Bancroft St,% Toledo, OH 43606% jpl@jpl.econ.utoledo.edufunfcn = fcnchk(f,length(varargin));p1 = pin;d1 = 0.618;d2 = 0.382;p2 = pin + xi;xarg = p1;f1 = feval(funfcn,xarg,varargin{:});itry = 0;    xarg = p2;    f2 = feval(funfcn,xarg,varargin{:});    while (f1 == f2 )  itry = itry+1;    p2 = p2 + xi;    xarg = p2;    f2 = feval(funfcn,xarg,varargin{:});    if itry == 10     error('problems in linmin --- itry is 10');    end;end;  if f1 <= f2 pm = p1; fm = f1; f1 = f2; p1 = p2;else pm = p2; fm = f2;end;xd = pm - p1;p2 = pm + xd;xarg = p2;f2 = feval(funfcn,xarg,varargin{:});while (f2 <= fm) xd = 2*xd; p2 = pm + xd;    xarg = p2;    f2 = feval(funfcn,xarg,varargin{:});end;x1 = d1*p1 + d2*p2;x2 = d2*p1 + d1*p2;xarg = x1;fx1 = feval(funfcn,xarg,varargin{:});xarg = x2;fx2 = feval(funfcn,xarg,varargin{:});while (sqrt(sum(p1-p2).^2) >= tol) x1 = d1*p1 + d2*p2; x2 = d2*p1 + d1*p2; xarg = x1;    fx1 = feval(funfcn,xarg,varargin{:});    xarg = x2;    fx2 = feval(funfcn,xarg,varargin{:});    if (fx1 <= fx2)     p2 = x2;    else     p1 = x1;    end;   end;   if (fx1 < fx2) pout = x1;else pout = x2;end;xarg = pout;    fout = feval(funfcn,xarg,varargin{:});