Golden Search method file consolidation

Question

Aaron 2013-10-2

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/88944-golden-search-method-file-consolidation

回答： Muhammad Saqib 2024-2-28

I had created two files (function and main) for a golden search problem. I would like to make just one file, type it in the command window without typing in any arguments(they would already be in the file) and have it run. Is this possible?

My code for the function file is:

function y=goldsec(x)
y = (4*x) - (1.8*x^2) + (1.2*x^3) - (0.3*x^4);

Main file:

function [x,fx,ea,iter]=goldmin(f,xl,xu,es,maxit,varargin)
% goldmin: minimization golden section search
%   [x,fx,ea,iter]=goldmin(f,xl,xu,es,maxit,p1,p2,...):
%     uses golden section search to find the minimum of f
% input:
%   f = name of function
%   xl, xu = lower and upper guesses
%   es = desired relative error (default = 0.0001%)
%   maxit = maximum allowable iterations (default = 50)
%   p1,p2,... = additional parameters used by f
% output:
%   x = location of minimum
%   fx = minimum function value
%   ea = approximate relative error (%)
%   iter = number of iterations
if nargin<3,error('at least 3 input arguments required'),end
if nargin<4|isempty(es), es=0.0001;end
if nargin<5|isempty(maxit), maxit=50;end
phi=(1+sqrt(5))/2;
iter=0;
while(1)
d = (phi-1)*(xu - xl);
x1 = xl + d;
x2 = xu - d;
if f(x1,varargin{:}) < f(x2,varargin{:})
  xopt = x1;
  xl = x2;
else
  xopt = x2;
  xu = x1;
end
iter=iter+1;
if xopt~=0, ea = (2 - phi) * abs((xu - xl) / xopt) * 100;end
if ea <= es | iter >= maxit,break,end
end
x=xopt;fx=f(xopt,varargin{:});