Adding an Extra Input Parameter to the Function

How can I add an extra input parameter to the function below? I want to add switch-case inside the function.

[features,history] = sequentialfs(@fun,X,Y,...
        'direction','forward','cv',cvt,'options',dsp_options);

 function cl_err = fun(xTrain,yTrain,xTest,yTest)
   .....  
 end

[Ameer Hamza]

What does switch case have to do with the input arguments? Please clarify your question.

[MB]

Actually I asked this question before I want to compare different classifiers. So I planned to pass an input parameter to the function to select different classifier in each iteration. Like below. Btw all suggestions are welcomed.

function cl_err = fun(xTrain,yTrain,xTest,yTest,i)
switch i
  case 1     
  ..... 
  case 2
  .... 
end 
end

Answer 1

[dpb]

Since sequentialfs is a builtin Toolbox function, you'll really not want to mess with it directly; write a wrapper function around it to use with a specific alternate name and make the modifications desired there; then have it pass the arguments on to the builtin function.

[MB]

Thank you very much.

Answer 2

[Guillaume]

[features,history] = sequentialfs(@(xTrain,yTrain,xTest,yTest) fun(xTrain,yTrain,xTest,classifier) , ...
      X,Y,'direction','forward','cv',cvt,'options',dsp_options);

function cl_err = fun(xTrain,yTrain,xTest,yTest,i)
    switch i
    ...

Basically, create an intermediate anonymous function

@(xTrain,yTrain,xTest,yTest) fun(xTrain,yTrain,xTest,classifier)

which calls fun with the extra argument classifier (which will become i in fun).

[MB]

Thank you very much.