MATLAB優化工具箱例如

Question

https://www.mathworks.com/help/optim/examples/banana-function-minimization.html

fun = @(x)(100*(x(2) - x(1)^2)^2 + (1 - x(1))^2); 
options = optimset('OutputFcn',@bananaout,'Display','off'); 
x0 = [-1.9,2]; 
[x,fval,eflag,output] = fminsearch(fun,x0,options); 
title 'Rosenbrock solution via fminsearch' 
Fcount = output.funcCount; 
disp(['Number of function evaluations for fminsearch was ',num2str(Fcount)]) 
disp(['Number of solver iterations for fminsearch was ',num2str(output.iterations)]) 

什麼是@bananaout這裏？

這是給我下面的錯誤，

??? Error using ==> feval 
Attempt to execute SCRIPT bananaout as a function: 
C:\Users\admin\Desktop\bananaout.m 

Error in ==> callAllOptimOutputFcns at 12 
    stop(i) = feval(OutputFcn{i},xOutputfcn,optimValues,state,varargin{:}); 

Error in ==> fminsearch>callOutputAndPlotFcns at 464 
      stop = callAllOptimOutputFcns(outputfcn,xOutputfcn,optimValues,state,varargin{:}) 
      || stop; 

Error in ==> fminsearch at 199 
    [xOutputfcn, optimValues, stop] = 
    callOutputAndPlotFcns(outputfcn,plotfcns,v(:,1),xOutputfcn,'init',itercount, ... 

Error in ==> test_optim at 9 
[x,fval,eflag,output] = fminsearch(fun,x0,options) 

Answer 1

按照商務部，Output Functions被優化在每個時間步長叫，使您能夠做這樣的事情的情節優化的進度。

在你的情況下，你會得到一個錯誤，因爲bananaout似乎是一個腳本，當它需要是一個函數（具體輸入 - 請參閱文檔的細節）。您是否碰巧將示例代碼保存在名爲bananaout的腳本中？如果是這樣，請重命名該腳本。

你可以看到，你有被執行所謂bananaout所有M代碼列表如下：

>> which bananaout -all

其中之一將是例子應該調用該函數，而另一個將是您創建並需要重命名/刪除的那個。